diff --git a/Cargo.lock b/Cargo.lock
index 0bad6271..d7b4b7a8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -273,7 +273,7 @@ dependencies = [
  "ark-std 0.4.0",
  "blake2",
  "derivative",
- "digest",
+ "digest 0.10.7",
  "sha2",
 ]
 
@@ -293,7 +293,7 @@ dependencies = [
  "ark-std 0.5.0",
  "blake2",
  "derivative",
- "digest",
+ "digest 0.10.7",
  "fnv",
  "merlin",
  "sha2",
@@ -359,7 +359,7 @@ dependencies = [
  "ark-serialize 0.4.2",
  "ark-std 0.4.0",
  "derivative",
- "digest",
+ "digest 0.10.7",
  "itertools 0.10.5",
  "num-bigint 0.4.6",
  "num-traits",
@@ -379,7 +379,7 @@ dependencies = [
  "ark-serialize 0.5.0",
  "ark-std 0.5.0",
  "arrayvec",
- "digest",
+ "digest 0.10.7",
  "educe",
  "itertools 0.13.0",
  "num-bigint 0.4.6",
@@ -541,7 +541,7 @@ checksum = "adb7b85a02b83d2f22f89bd5cac66c9c89474240cb6207cb1efc16d098e822a5"
 dependencies = [
  "ark-serialize-derive 0.4.2",
  "ark-std 0.4.0",
- "digest",
+ "digest 0.10.7",
  "num-bigint 0.4.6",
 ]
 
@@ -554,7 +554,7 @@ dependencies = [
  "ark-serialize-derive 0.5.0",
  "ark-std 0.5.0",
  "arrayvec",
- "digest",
+ "digest 0.10.7",
  "num-bigint 0.4.6",
 ]
 
@@ -1192,7 +1192,7 @@ version = "0.10.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "46502ad458c9a52b69d4d4d32775c788b7a1b85e8bc9d482d92250fc0e3f8efe"
 dependencies = [
- "digest",
+ "digest 0.10.7",
 ]
 
 [[package]]
@@ -1622,6 +1622,12 @@ dependencies = [
  "nssa_core",
 ]
 
+[[package]]
+name = "cmov"
+version = "0.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c9ea0ac24bc397ab3c98583a3c9ba74fa56b09a4449bbe172b9b1ddb016027a"
+
 [[package]]
 name = "cobs"
 version = "0.3.0"
@@ -1757,6 +1763,12 @@ version = "0.9.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2459377285ad874054d797f3ccebf984978aa39129f6eafde5cdc8315b612f8"
 
+[[package]]
+name = "const-oid"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a6ef517f0926dd24a1582492c791b6a4818a4d94e789a334894aa15b0d12f55c"
+
 [[package]]
 name = "const-str"
 version = "0.4.3"
@@ -2023,17 +2035,22 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "77727bb15fa921304124b128af125e7e3b968275d1b108b379190264f4423710"
 dependencies = [
+ "getrandom 0.4.2",
  "hybrid-array",
+ "rand_core 0.10.1",
 ]
 
 [[package]]
 name = "crypto_primitives_bench"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "criterion",
  "key_protocol",
  "nssa_core",
  "rand 0.8.5",
+ "serde",
+ "serde_json",
 ]
 
 [[package]]
@@ -2045,6 +2062,15 @@ dependencies = [
  "cipher 0.4.4",
 ]
 
+[[package]]
+name = "ctutils"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d5515a3834141de9eafb9717ad39eea8247b5674e6066c404e8c4b365d2a29e"
+dependencies = [
+ "cmov",
+]
+
 [[package]]
 name = "curve25519-dalek"
 version = "4.1.3"
@@ -2054,7 +2080,7 @@ dependencies = [
  "cfg-if",
  "cpufeatures 0.2.17",
  "curve25519-dalek-derive",
- "digest",
+ "digest 0.10.7",
  "fiat-crypto",
  "rustc_version",
  "serde",
@@ -2186,7 +2212,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7ab67060fc6b8ef687992d439ca0fa36e7ed17e9a0b16b25b601e8757df720de"
 dependencies = [
  "data-encoding",
- "syn 1.0.109",
+ "syn 2.0.117",
 ]
 
 [[package]]
@@ -2195,11 +2221,21 @@ version = "0.7.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e7c1832837b905bbfb5101e07cc24c8deddf52f93225eee6ead5f4d63d53ddcb"
 dependencies = [
- "const-oid",
+ "const-oid 0.9.6",
  "pem-rfc7468",
  "zeroize",
 ]
 
+[[package]]
+name = "der"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "71fd89660b2dc699704064e59e9dba0147b903e85319429e131620d022be411b"
+dependencies = [
+ "const-oid 0.10.2",
+ "zeroize",
+]
+
 [[package]]
 name = "der-parser"
 version = "10.0.0"
@@ -2318,11 +2354,21 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
 dependencies = [
  "block-buffer 0.10.4",
- "const-oid",
+ "const-oid 0.9.6",
  "crypto-common 0.1.7",
  "subtle",
 ]
 
+[[package]]
+name = "digest"
+version = "0.11.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1dd6dbb5841937940781866fa1281a1ff7bd3bf827091440879f9994983d5c2"
+dependencies = [
+ "block-buffer 0.12.0",
+ "crypto-common 0.2.1",
+]
+
 [[package]]
 name = "directories"
 version = "6.0.0"
@@ -2416,7 +2462,7 @@ version = "0.2.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9ac1e888d6830712d565b2f3a974be3200be9296bc1b03db8251a4cbf18a4a34"
 dependencies = [
- "digest",
+ "digest 0.10.7",
  "futures",
  "rand 0.8.5",
  "reqwest",
@@ -2448,13 +2494,13 @@ version = "0.16.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ee27f32b5c5292967d2d4a9d7f1e0b0aed2c15daded5a60300e4abb9d8020bca"
 dependencies = [
- "der",
- "digest",
+ "der 0.7.10",
+ "digest 0.10.7",
  "elliptic-curve",
  "rfc6979",
  "serdect",
  "signature",
- "spki",
+ "spki 0.7.3",
 ]
 
 [[package]]
@@ -2463,7 +2509,7 @@ version = "2.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "115531babc129696a58c64a4fef0a8bf9e9698629fb97e9e40767d235cfbcd53"
 dependencies = [
- "pkcs8",
+ "pkcs8 0.10.2",
  "serde",
  "signature",
 ]
@@ -2525,12 +2571,12 @@ checksum = "b5e6043086bf7973472e0c7dff2142ea0b680d30e18d9cc40f267efbf222bd47"
 dependencies = [
  "base16ct",
  "crypto-bigint",
- "digest",
+ "digest 0.10.7",
  "ff",
  "generic-array 0.14.7",
  "group",
  "pem-rfc7468",
- "pkcs8",
+ "pkcs8 0.10.2",
  "rand_core 0.6.4",
  "sec1",
  "serdect",
@@ -2670,7 +2716,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
  "libc",
- "windows-sys 0.52.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -3436,7 +3482,7 @@ version = "0.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6c49c37c09c17a53d937dfbb742eb3a961d65a994e6bcdcf37e7399d0cc8ab5e"
 dependencies = [
- "digest",
+ "digest 0.10.7",
 ]
 
 [[package]]
@@ -3558,6 +3604,7 @@ version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8655f91cd07f2b9d0c24137bd650fe69617773435ee5ec83022377777ce65ef1"
 dependencies = [
+ "ctutils",
  "typenum",
 ]
 
@@ -4504,6 +4551,26 @@ dependencies = [
  "cpufeatures 0.2.17",
 ]
 
+[[package]]
+name = "keccak"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9e24a010dd405bd7ed803e5253182815b41bf2e6a80cc3bfc066658e03a198aa"
+dependencies = [
+ "cfg-if",
+ "cpufeatures 0.3.0",
+]
+
+[[package]]
+name = "kem"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "01737161ba802849cfd486b5bd209d38ba4943494c249a8126005170c7621edd"
+dependencies = [
+ "crypto-common 0.2.1",
+ "rand_core 0.10.1",
+]
+
 [[package]]
 name = "key_protocol"
 version = "0.1.0"
@@ -4518,6 +4585,7 @@ dependencies = [
  "hmac-sha512",
  "itertools 0.14.0",
  "k256",
+ "ml-kem",
  "nssa",
  "nssa_core",
  "rand 0.8.5",
@@ -6182,7 +6250,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "58c38e2799fc0978b65dfff8023ec7843e2330bb462f19198840b34b6582397d"
 dependencies = [
  "byteorder",
- "keccak",
+ "keccak 0.1.6",
  "rand_core 0.6.4",
  "zeroize",
 ]
@@ -6245,6 +6313,31 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "ml-kem"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5e15f3e5b957493873e396a66914e83e616b6afe335cdef7efe5c6e1216aba66"
+dependencies = [
+ "hybrid-array",
+ "kem",
+ "module-lattice",
+ "pkcs8 0.11.0",
+ "rand_core 0.10.1",
+ "sha3",
+]
+
+[[package]]
+name = "module-lattice"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c61b87c9683ab7cb1c6871d261ad5479b6b10ceb52c4352aaca3b5d35a8febe"
+dependencies = [
+ "ctutils",
+ "hybrid-array",
+ "num-traits",
+]
+
 [[package]]
 name = "moka"
 version = "0.12.15"
@@ -6497,10 +6590,10 @@ dependencies = [
  "ark-ec 0.4.2",
  "ark-ff 0.4.2",
  "ark-serialize 0.4.2",
- "digest",
+ "digest 0.10.7",
  "generic-array 0.14.7",
  "hex",
- "keccak",
+ "keccak 0.1.6",
  "log",
  "rand 0.8.5",
  "zeroize",
@@ -6590,7 +6683,7 @@ dependencies = [
  "bytemuck",
  "bytesize",
  "chacha20",
- "k256",
+ "ml-kem",
  "risc0-zkvm",
  "serde",
  "serde_json",
@@ -7142,9 +7235,9 @@ version = "0.7.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c8ffb9f10fa047879315e6625af03c164b16962a5368d724ed16323b68ace47f"
 dependencies = [
- "der",
- "pkcs8",
- "spki",
+ "der 0.7.10",
+ "pkcs8 0.10.2",
+ "spki 0.7.3",
 ]
 
 [[package]]
@@ -7153,8 +7246,18 @@ version = "0.10.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f950b2377845cebe5cf8b5165cb3cc1a5e0fa5cfa3e1f7f55707d8fd82e0a7b7"
 dependencies = [
- "der",
- "spki",
+ "der 0.7.10",
+ "spki 0.7.3",
+]
+
+[[package]]
+name = "pkcs8"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "451913da69c775a56034ea8d9003d27ee8948e12443eae7c038ba100a4f21cb7"
+dependencies = [
+ "der 0.8.0",
+ "spki 0.8.0",
 ]
 
 [[package]]
@@ -7627,7 +7730,7 @@ dependencies = [
  "quinn-udp",
  "rustc-hash",
  "rustls",
- "socket2 0.5.10",
+ "socket2 0.6.3",
  "thiserror 2.0.18",
  "tokio",
  "tracing",
@@ -7664,9 +7767,9 @@ dependencies = [
  "cfg_aliases",
  "libc",
  "once_cell",
- "socket2 0.5.10",
+ "socket2 0.6.3",
  "tracing",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -8126,7 +8229,7 @@ dependencies = [
  "anyhow",
  "bytemuck",
  "cfg-if",
- "keccak",
+ "keccak 0.1.6",
  "liblzma",
  "paste",
  "rayon",
@@ -8309,7 +8412,7 @@ dependencies = [
  "borsh",
  "bytemuck",
  "cfg-if",
- "digest",
+ "digest 0.10.7",
  "ff",
  "hex",
  "hex-literal 0.4.1",
@@ -8348,7 +8451,7 @@ dependencies = [
  "gdbstub_arch",
  "gimli",
  "hex",
- "keccak",
+ "keccak 0.1.6",
  "lazy-regex",
  "num-bigint 0.4.6",
  "num-traits",
@@ -8466,16 +8569,16 @@ version = "0.9.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b8573f03f5883dcaebdfcf4725caa1ecb9c15b2ef50c43a07b816e06799bb12d"
 dependencies = [
- "const-oid",
- "digest",
+ "const-oid 0.9.6",
+ "digest 0.10.7",
  "num-bigint-dig",
  "num-integer",
  "num-traits",
  "pkcs1",
- "pkcs8",
+ "pkcs8 0.10.2",
  "rand_core 0.6.4",
  "signature",
- "spki",
+ "spki 0.7.3",
  "subtle",
  "zeroize",
 ]
@@ -8585,7 +8688,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys 0.52.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -8643,7 +8746,7 @@ dependencies = [
  "security-framework",
  "security-framework-sys",
  "webpki-root-certs 0.26.11",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -8791,9 +8894,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d3e97a565f76233a6003f9f5c54be1d9c5bdfa3eccfb189469f11ec4901c47dc"
 dependencies = [
  "base16ct",
- "der",
+ "der 0.7.10",
  "generic-array 0.14.7",
- "pkcs8",
+ "pkcs8 0.10.2",
  "serdect",
  "subtle",
  "zeroize",
@@ -9181,7 +9284,7 @@ checksum = "e3bf829a2d51ab4a5ddf1352d8470c140cadc8301b2ae1789db023f01cedd6ba"
 dependencies = [
  "cfg-if",
  "cpufeatures 0.2.17",
- "digest",
+ "digest 0.10.7",
 ]
 
 [[package]]
@@ -9192,7 +9295,17 @@ checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
 dependencies = [
  "cfg-if",
  "cpufeatures 0.2.17",
- "digest",
+ "digest 0.10.7",
+]
+
+[[package]]
+name = "sha3"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be176f1a57ce4e3d31c1a166222d9768de5954f811601fb7ca06fc8203905ce1"
+dependencies = [
+ "digest 0.11.3",
+ "keccak 0.2.0",
 ]
 
 [[package]]
@@ -9226,7 +9339,7 @@ version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "77549399552de45a898a580c1b41d445bf730df867cc44e6c0233bbc4b8329de"
 dependencies = [
- "digest",
+ "digest 0.10.7",
  "rand_core 0.6.4",
 ]
 
@@ -9325,7 +9438,17 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d91ed6c858b01f942cd56b37a94b3e0a1798290327d1236e4d9cf4eaca44d29d"
 dependencies = [
  "base64ct",
- "der",
+ "der 0.7.10",
+]
+
+[[package]]
+name = "spki"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1d9efca8738c78ee9484207732f728b1ef517bbb1833d6fc0879ca898a522f6f"
+dependencies = [
+ "base64ct",
+ "der 0.8.0",
 ]
 
 [[package]]
@@ -9570,7 +9693,7 @@ dependencies = [
  "getrandom 0.4.2",
  "once_cell",
  "rustix",
- "windows-sys 0.52.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -10986,7 +11109,7 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
 dependencies = [
- "windows-sys 0.52.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index ca9880ab..ae16f75c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -157,6 +157,7 @@ k256 = { version = "0.13.3", features = [
   "serde",
   "pem",
 ] }
+ml-kem = { version = "0.3", features = ["hazmat"] }
 elliptic-curve = { version = "0.13.8", features = ["arithmetic"] }
 actix-web = { version = "4.13.0", default-features = false, features = [
   "macros",
diff --git a/artifacts/program_methods/authenticated_transfer.bin b/artifacts/program_methods/authenticated_transfer.bin
index 56feb4b9..5266b5c3 100644
Binary files a/artifacts/program_methods/authenticated_transfer.bin and b/artifacts/program_methods/authenticated_transfer.bin differ
diff --git a/artifacts/program_methods/bridge.bin b/artifacts/program_methods/bridge.bin
index 3eacbc9d..6cd3bfeb 100644
Binary files a/artifacts/program_methods/bridge.bin and b/artifacts/program_methods/bridge.bin differ
diff --git a/artifacts/program_methods/faucet.bin b/artifacts/program_methods/faucet.bin
index 2399f4f8..7f715d6d 100644
Binary files a/artifacts/program_methods/faucet.bin and b/artifacts/program_methods/faucet.bin differ
diff --git a/artifacts/program_methods/pinata.bin b/artifacts/program_methods/pinata.bin
index 0f305832..647894bd 100644
Binary files a/artifacts/program_methods/pinata.bin and b/artifacts/program_methods/pinata.bin differ
diff --git a/artifacts/program_methods/pinata_token.bin b/artifacts/program_methods/pinata_token.bin
index e3751f5f..31c2cf18 100644
Binary files a/artifacts/program_methods/pinata_token.bin and b/artifacts/program_methods/pinata_token.bin differ
diff --git a/artifacts/program_methods/privacy_preserving_circuit.bin b/artifacts/program_methods/privacy_preserving_circuit.bin
index 99cfd7ee..664a3e46 100644
Binary files a/artifacts/program_methods/privacy_preserving_circuit.bin and b/artifacts/program_methods/privacy_preserving_circuit.bin differ
diff --git a/artifacts/program_methods/vault.bin b/artifacts/program_methods/vault.bin
index 31629aa3..9606f90f 100644
Binary files a/artifacts/program_methods/vault.bin and b/artifacts/program_methods/vault.bin differ
diff --git a/artifacts/test_program_methods/auth_asserting_noop.bin b/artifacts/test_program_methods/auth_asserting_noop.bin
index d0b8b80d..4dbe0f19 100644
Binary files a/artifacts/test_program_methods/auth_asserting_noop.bin and b/artifacts/test_program_methods/auth_asserting_noop.bin differ
diff --git a/artifacts/test_program_methods/auth_transfer_proxy.bin b/artifacts/test_program_methods/auth_transfer_proxy.bin
index 7d728367..8c75514e 100644
Binary files a/artifacts/test_program_methods/auth_transfer_proxy.bin and b/artifacts/test_program_methods/auth_transfer_proxy.bin differ
diff --git a/artifacts/test_program_methods/changer_claimer.bin b/artifacts/test_program_methods/changer_claimer.bin
index a98fa099..81b1b106 100644
Binary files a/artifacts/test_program_methods/changer_claimer.bin and b/artifacts/test_program_methods/changer_claimer.bin differ
diff --git a/artifacts/test_program_methods/clock_chain_caller.bin b/artifacts/test_program_methods/clock_chain_caller.bin
index 0407dc83..bf010572 100644
Binary files a/artifacts/test_program_methods/clock_chain_caller.bin and b/artifacts/test_program_methods/clock_chain_caller.bin differ
diff --git a/artifacts/test_program_methods/data_changer.bin b/artifacts/test_program_methods/data_changer.bin
index 1b1e4478..6b9a225e 100644
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diff --git a/docs/LEZ testnet v0.1 tutorials/token-transfer.md b/docs/LEZ testnet v0.1 tutorials/token-transfer.md
index 3a1ef43f..e3d04663 100644
--- a/docs/LEZ testnet v0.1 tutorials/token-transfer.md	
+++ b/docs/LEZ testnet v0.1 tutorials/token-transfer.md	
@@ -155,7 +155,7 @@ wallet account new private
 # Output:
 Generated new account with account_id Private/HacPU3hakLYzWtSqUPw6TUr8fqoMieVWovsUR6sJf7cL
 With npk e6366f79d026c8bd64ae6b3d601f0506832ec682ab54897f205fffe64ec0d951
-With vpk 02ddc96d0eb56e00ce14994cfdaec5ae1f76244180a919545983156e3519940a17
+With vpk <1184-byte ML-KEM-768 encapsulation key, hex-encoded>
 ```
 
 > [!Tip]
@@ -231,19 +231,29 @@ wallet account new private-accounts-key
 # Output:
 Generated new private accounts key at path /1
 With npk 0c95ebc4b3830f53da77bb0b80a276a776cdcf6410932acc718dcdb3f788a00e
-With vpk 039fd12a3674a880d3e917804129141e4170d419d1f9e28a3dcf979c1f2369cb72
+With vpk <1184-byte ML-KEM-768 encapsulation key, hex-encoded>
 ```
 
-> [!Tip]
-> Ignore the account ID here and use the `npk` and `vpk` values to send to a foreign private account.
+> [!Important]
+> The VPK is now a 1184-byte ML-KEM-768 encapsulation key — too large to copy-paste into a command.
+> The recommended workflow is:
+>
+> **Recipient:** export both keys to a single file and send the file to the sender (e.g. as an email attachment):
+> ```bash
+> wallet account show-keys --account-id Private/<account-id> > recipient.keys
+> # Send recipient.keys to the sender out-of-band
+> ```
+> The file contains two lines: the npk (hex) on line 1, the vpk (hex) on line 2.
+>
+> **Sender:** reference the received file with `--to-keys`:
 
-### b. Send 3 tokens using the recipient’s npk and vpk
+### b. Send 3 tokens using the recipient’s keys file
 
 ```bash
+# The sender has received recipient.keys from the recipient out-of-band
 wallet auth-transfer send \
     --from Public/Ev1JprP9BmhbFVQyBcbznU8bAXcwrzwRoPTetXdQPAWS \
-    --to-npk 0c95ebc4b3830f53da77bb0b80a276a776cdcf6410932acc718dcdb3f788a00e \
-    --to-vpk 039fd12a3674a880d3e917804129141e4170d419d1f9e28a3dcf979c1f2369cb72 \
+    --to-keys recipient.keys \
     --amount 3
 ```
 
@@ -270,18 +280,19 @@ wallet account new private-accounts-key
 # Output:
 Generated new private accounts key at path /2
 With npk a3f7c21b8e905d4f6a1bc783d0e2f94c1d5a6b7e8f9012345678abcdef012345
-With vpk 03b1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6071819202122232425262728292a2b2c
+With vpk <1184-byte ML-KEM-768 encapsulation key, hex-encoded>
 ```
 
 Alice shares the `npk` and `vpk` values with Bob and Charlie out of band.
 
 ### b. Bob sends 10 tokens to Alice using identifier 1
 
+Bob uses the received `alice.keys` file:
+
 ```bash
 wallet auth-transfer send \
     --from Public/BobXqJprP9BmhbFVQyBcbznU8bAXcwrzwRoPTetXdQPA \
-    --to-npk a3f7c21b8e905d4f6a1bc783d0e2f94c1d5a6b7e8f9012345678abcdef012345 \
-    --to-vpk 03b1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6071819202122232425262728292a2b2c \
+    --to-keys alice.keys \
     --to-identifier 1 \
     --amount 10
 ```
@@ -291,8 +302,7 @@ wallet auth-transfer send \
 ```bash
 wallet auth-transfer send \
     --from Public/CharlieYrP9BmhbFVQyBcbznU8bAXcwrzwRoPTetXdQPB \
-    --to-npk a3f7c21b8e905d4f6a1bc783d0e2f94c1d5a6b7e8f9012345678abcdef012345 \
-    --to-vpk 03b1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6071819202122232425262728292a2b2c \
+    --to-keys alice.keys \
     --to-identifier 2 \
     --amount 5
 ```
diff --git a/docs/specs.md b/docs/specs.md
new file mode 100644
index 00000000..1e403776
--- /dev/null
+++ b/docs/specs.md
@@ -0,0 +1,169 @@
+# LEE v0.3 specifications for Key Agreement
+
+## LEE v0.3 basic types and constants
+
+```rust
+/// The ML-KEM-768 KEM ciphertext produced during encapsulation (1088 bytes) of a message.
+/// `EphemeralPublicKey` is used to not confuse the ciphertext of an encrypted private account.
+type EphemeralPublicKey = [u8; 1088];
+
+/// Private account Viewing Public Key is a ML-KEM-768 encapsulation key (1184 bytes).
+type ViewingPublicKey = [u8; 1184];
+/// The ML-KEM-768 shared secret (32 bytes).
+type SharedSecretKey = [u8; 32];
+
+struct EncryptedAccountData {
+    ciphertext: Ciphertext,
+    epk: EphemeralPublicKey,
+    view_tag: u8,           // 1-byte view tag
+}
+```
+
+#### Key agreement and shared secret
+
+When creating a private account output, the sender uses the recipient's viewing public key to encapsulate a random message that is used to establish a shared secret between the sender and recipient:
+
+- Sender: $(\mathsf{ss},\, \mathsf{epk}) = \mathsf{encapsulate}(\mathsf{vpk\_recipient})$. The 1088-byte ciphertext `epk` is included in the transaction as the `EphemeralPublicKey` field.
+- Receiver: $\mathsf{ss} = \mathsf{decapsulate}(\mathsf{epk},\, vsk.d,\, vsk.z)$
+
+where `vpk` is the receiver's `ViewingPublicKey` and `(vsk.d, vsk.z)` are the two 32-byte halves of the receiver's `ViewingSecretKey`.
+
+#### KDF
+
+```rust
+fn kdf(
+    shared_secret: &SharedSecretKey,    // 32-byte output of the KEM
+    commitment: &Commitment,            // 32-byte output commitment
+    output_index: u32,                  // index of this output within the tx (LE)
+) -> [u8; 32] {
+    let mut bytes = Vec::new();
+    bytes.extend_from_slice(b"NSSA/v0.2/KDF-SHA256/");
+    bytes.extend_from_slice(&shared_secret.0);
+    bytes.extend_from_slice(&commitment.to_byte_array());
+    bytes.extend_from_slice(&output_index.to_le_bytes());
+    sha256(bytes)
+}
+```
+
+### Circuit input
+
+```rust
+pub enum InputAccountIdentity {
+    /// Public account. The guest reads pre/post state from program_outputs and emits no
+    /// commitment, ciphertext, or nullifier.
+    Public,
+
+    /// Initialization of a standalone private account the caller owns.
+    /// Pre-state must be Account::default().
+    /// AccountId = AccountId::from_private(npk(nsk), identifier).
+    PrivateAuthorizedInit {
+        ssk: SharedSecretKey,
+        nsk: NullifierSecretKey,
+        identifier: Identifier,
+    },
+
+    /// Update of an existing standalone private account the caller owns.
+    /// Membership proof for the current on-chain commitment is required.
+    PrivateAuthorizedUpdate {
+        ssk: SharedSecretKey,
+        nsk: NullifierSecretKey,
+        membership_proof: MembershipProof,
+        identifier: Identifier,
+    },
+
+    /// Initialization of a standalone private account the caller does not own
+    /// (e.g. a recipient who does not yet exist on chain). No nsk, no membership proof.
+    PrivateUnauthorized {
+        npk: NullifierPublicKey,
+        ssk: SharedSecretKey,
+        identifier: Identifier,
+    },
+
+    /// Initialization of a private PDA.
+    /// Authorization comes via Claim::Pda(seed) or the caller's pda_seeds.
+    /// The identifier diversifies the PDA within the (program_id, seed, npk) family.
+    PrivatePdaInit {
+        npk: NullifierPublicKey,
+        ssk: SharedSecretKey,
+        identifier: Identifier,
+        /// When `Some((seed, authority_program_id))`, the circuit binds this position via
+        /// `AccountId::for_private_pda(authority_program_id, seed, npk, identifier) == pre_state.account_id`
+        /// rather than requiring a `Claim::Pda` or caller `pda_seeds`. The `pre_state` must
+        /// have `is_authorized == false`.
+        seed: Option<(PdaSeed, ProgramId)>,
+    },
+
+    /// Update of an existing private PDA. npk is derived from nsk.
+    /// Membership proof is required.
+    PrivatePdaUpdate {
+        ssk: SharedSecretKey,
+        nsk: NullifierSecretKey,
+        membership_proof: MembershipProof,
+        identifier: Identifier,
+        /// When `Some((seed, authority_program_id))`, the circuit binds this position via
+        /// `AccountId::for_private_pda(authority_program_id, seed, npk, identifier) == pre_state.account_id`
+        /// rather than requiring a caller `pda_seeds`. The `pre_state` must have
+        /// `is_authorized == false`.
+        seed: Option<(PdaSeed, ProgramId)>,
+    },
+}
+```
+
+The `ssk` field carries the **shared secret key** — the 32-byte shared secret used to encrypt the post-state. Note that the key protocol uses `ssk` for "spending secret key" (the master key that derives `nsk` and `vsk`); here `ssk` means the per-output KEM shared secret. It is established via ML-KEM-768:
+
+- Sender: `(ssk, epk) = encapsulate(vpk)`
+- Receiver: `ssk = decapsulate(epk, vsk.d, vsk.z)`
+
+where `epk` is the ML-KEM-768 ciphertext (1088 bytes) stored as the `EphemeralPublicKey`, `vpk` is the recipient's `ViewingPublicKey` (1184 bytes), and `(vsk.d, vsk.z)` are the 32-byte seed halves of the recipient's `ViewingSecretKey`.
+
+## Encrypted private account discovery and tagging
+
+### Ephemeral view tags
+
+Each private account output includes a 1-byte view tag to allow wallets to quickly filter outputs before attempting decryption:
+
+$$\mathsf{ViewTag} = \mathsf{SHA256}(\text{"/LEE/v0.3/ViewTag/"} \;||\; \mathsf{Npk} \;||\; \mathsf{Vpk})[0]$$
+
+where `Npk` is the 32-byte nullifier public key and `Vpk` is the 1184 byte `ViewingPublicKey` of the recipient. On average only 1 in 256 outputs will pass this filter for a given account, avoiding expensive ML-KEM decapsulation on irrelevant outputs.
+
+### Private account discovery with viewing keys
+
+1. For each encrypted output, compute the expected view tag from `(Npk, Vpk)`. Skip if it does not match.
+2. Decapsulate using ML-KEM-768: `ss = decapsulate(epk, vsk.d, vsk.z)`.
+3. Run `kdf(ss, commitment, output_index)` to derive the symmetric key.
+4. Decrypt the ciphertext with ChaCha20.
+5. Parse the 81-byte header to recover `PrivateAccountKind`.
+6. Parse the remaining bytes to recover the `Account`.
+7. Recompute the account ID from the kind and verify that `Commitment::new(account_id, account)` equals the on-chain commitment. Discard on mismatch (false positive).
+
+```rust
+fn private_account_discovery(
+    tx: &PrivacyPreservingTransaction,
+    vsk: &ViewingSecretKey,
+    npk: &NullifierPublicKey,
+    vpk: &ViewingPublicKey,
+) -> Vec<(PrivateAccountKind, Account)> {
+    let expected_tag = EncryptedAccountData::compute_view_tag(npk, vpk);
+    let mut discovered = Vec::new();
+
+    for (output_index, (encrypted_account, commitment)) in tx.message.encrypted_private_post_states
+        .iter()
+        .zip(&tx.message.new_commitments)
+        .enumerate()
+    {
+        if encrypted_account.view_tag != expected_tag {
+            continue;
+        }
+        let ss = SharedSecretKey::decapsulate(&encrypted_account.epk, &vsk.d, &vsk.z);
+        if let Some((kind, account)) = EncryptionScheme::decrypt(
+            &encrypted_account.ciphertext, &ss, commitment, output_index as u32
+        ) {
+            let account_id = AccountId::for_private_account(npk, &kind);
+            if Commitment::new(&account_id, &account) == *commitment {
+                discovered.push((kind, account));
+            }
+        }
+    }
+    discovered
+}
+```
diff --git a/integration_tests/tests/amm.rs b/integration_tests/tests/amm.rs
index b7a747f1..9f953001 100644
--- a/integration_tests/tests/amm.rs
+++ b/integration_tests/tests/amm.rs
@@ -132,6 +132,7 @@ async fn amm_public() -> Result<()> {
         to: Some(public_mention(recipient_account_id_1)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 7,
     };
@@ -158,6 +159,7 @@ async fn amm_public() -> Result<()> {
         to: Some(public_mention(recipient_account_id_2)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 7,
     };
@@ -530,6 +532,7 @@ async fn amm_new_pool_using_labels() -> Result<()> {
         to: Some(public_mention(holding_a_id)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 5,
     };
@@ -551,6 +554,7 @@ async fn amm_new_pool_using_labels() -> Result<()> {
         to: Some(public_mention(holding_b_id)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 5,
     };
diff --git a/integration_tests/tests/ata.rs b/integration_tests/tests/ata.rs
index d0eddeae..37006aee 100644
--- a/integration_tests/tests/ata.rs
+++ b/integration_tests/tests/ata.rs
@@ -260,6 +260,7 @@ async fn transfer_and_burn_via_ata() -> Result<()> {
             to: Some(public_mention(sender_ata_id)),
             to_npk: None,
             to_vpk: None,
+            to_keys: None,
             to_identifier: Some(0),
             amount: fund_amount,
         }),
@@ -487,6 +488,7 @@ async fn transfer_via_ata_private_owner() -> Result<()> {
             to: Some(public_mention(sender_ata_id)),
             to_npk: None,
             to_vpk: None,
+            to_keys: None,
             to_identifier: Some(0),
             amount: fund_amount,
         }),
@@ -598,6 +600,7 @@ async fn burn_via_ata_private_owner() -> Result<()> {
             to: Some(public_mention(holder_ata_id)),
             to_npk: None,
             to_vpk: None,
+            to_keys: None,
             to_identifier: Some(0),
             amount: fund_amount,
         }),
diff --git a/integration_tests/tests/auth_transfer/private.rs b/integration_tests/tests/auth_transfer/private.rs
index 6a8eed82..996223ae 100644
--- a/integration_tests/tests/auth_transfer/private.rs
+++ b/integration_tests/tests/auth_transfer/private.rs
@@ -12,8 +12,9 @@ use nssa::{
     privacy_preserving_transaction::circuit::ProgramWithDependencies, program::Program,
 };
 use nssa_core::{
-    InputAccountIdentity, NullifierPublicKey, account::AccountWithMetadata,
-    encryption::shared_key_derivation::Secp256k1Point,
+    InputAccountIdentity, NullifierPublicKey,
+    account::AccountWithMetadata,
+    encryption::{EphemeralPublicKey, MlKem768EncapsulationKey, ViewingPublicKey},
 };
 use sequencer_service_rpc::RpcClient as _;
 use tokio::test;
@@ -38,6 +39,7 @@ async fn private_transfer_to_owned_account() -> Result<()> {
         to: Some(private_mention(to)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -71,13 +73,14 @@ async fn private_transfer_to_foreign_account() -> Result<()> {
     let from: AccountId = ctx.existing_private_accounts()[0];
     let to_npk = NullifierPublicKey([42; 32]);
     let to_npk_string = hex::encode(to_npk.0);
-    let to_vpk = Secp256k1Point::from_scalar(to_npk.0);
+    let to_vpk = ViewingPublicKey::from_seed(&[0_u8; 32], &[1_u8; 32]);
 
     let command = Command::AuthTransfer(AuthTransferSubcommand::Send {
         from: private_mention(from),
         to: None,
         to_npk: Some(to_npk_string),
-        to_vpk: Some(hex::encode(to_vpk.0)),
+        to_vpk: Some(hex::encode(to_vpk.to_bytes())),
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -127,6 +130,7 @@ async fn deshielded_transfer_to_public_account() -> Result<()> {
         to: Some(public_mention(to)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -189,7 +193,8 @@ async fn private_transfer_to_owned_account_using_claiming_path() -> Result<()> {
         from: private_mention(from),
         to: None,
         to_npk: Some(hex::encode(to.key_chain.nullifier_public_key.0)),
-        to_vpk: Some(hex::encode(&to.key_chain.viewing_public_key.0)),
+        to_vpk: Some(hex::encode(to.key_chain.viewing_public_key.to_bytes())),
+        to_keys: None,
         to_identifier: Some(to.kind.identifier()),
         amount: 100,
     });
@@ -239,6 +244,7 @@ async fn shielded_transfer_to_owned_private_account() -> Result<()> {
         to: Some(private_mention(to)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -274,14 +280,15 @@ async fn shielded_transfer_to_foreign_account() -> Result<()> {
 
     let to_npk = NullifierPublicKey([42; 32]);
     let to_npk_string = hex::encode(to_npk.0);
-    let to_vpk = Secp256k1Point::from_scalar(to_npk.0);
+    let to_vpk = ViewingPublicKey::from_seed(&[0_u8; 32], &[1_u8; 32]);
     let from: AccountId = ctx.existing_public_accounts()[0];
 
     let command = Command::AuthTransfer(AuthTransferSubcommand::Send {
         from: public_mention(from),
         to: None,
         to_npk: Some(to_npk_string),
-        to_vpk: Some(hex::encode(to_vpk.0)),
+        to_vpk: Some(hex::encode(to_vpk.to_bytes())),
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -351,7 +358,8 @@ async fn private_transfer_to_owned_account_continuous_run_path() -> Result<()> {
         from: private_mention(from),
         to: None,
         to_npk: Some(hex::encode(to.key_chain.nullifier_public_key.0)),
-        to_vpk: Some(hex::encode(&to.key_chain.viewing_public_key.0)),
+        to_vpk: Some(hex::encode(to.key_chain.viewing_public_key.to_bytes())),
+        to_keys: None,
         to_identifier: Some(to.kind.identifier()),
         amount: 100,
     });
@@ -452,6 +460,7 @@ async fn private_transfer_using_from_label() -> Result<()> {
         to: Some(private_mention(to)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -545,7 +554,7 @@ async fn shielded_transfers_to_two_identifiers_same_npk() -> Result<()> {
     };
 
     let npk_hex = hex::encode(npk.0);
-    let vpk_hex = hex::encode(vpk.0);
+    let vpk_hex = hex::encode(vpk.to_bytes());
 
     let identifier_1 = 1_u128;
     let identifier_2 = 2_u128;
@@ -560,6 +569,7 @@ async fn shielded_transfers_to_two_identifiers_same_npk() -> Result<()> {
             to: None,
             to_npk: Some(npk_hex.clone()),
             to_vpk: Some(vpk_hex.clone()),
+            to_keys: None,
             to_identifier: Some(identifier_1),
             amount: 100,
         }),
@@ -573,6 +583,7 @@ async fn shielded_transfers_to_two_identifiers_same_npk() -> Result<()> {
             to: None,
             to_npk: Some(npk_hex),
             to_vpk: Some(vpk_hex),
+            to_keys: None,
             to_identifier: Some(identifier_2),
             amount: 200,
         }),
@@ -654,8 +665,9 @@ async fn ppt_cant_chain_call_faucet() -> Result<()> {
     let auth_transfer_program_id = Program::authenticated_transfer_program().id();
     let nsk: nssa_core::NullifierSecretKey = [3; 32];
     let npk = NullifierPublicKey::from(&nsk);
-    let vpk = Secp256k1Point::from_scalar([4; 32]);
-    let ssk = SharedSecretKey::new([55; 32], &vpk);
+    let _vpk = MlKem768EncapsulationKey::from_bytes(vec![4_u8; 1184]).unwrap();
+    let ssk = SharedSecretKey([55_u8; 32]);
+    let _epk = EphemeralPublicKey(vec![55_u8; 1088]);
     let attacker_vault_id = {
         let seed = vault_core::compute_vault_seed(attacker_id);
         AccountId::for_private_pda(&vault_program_id, &seed, &npk, 1337)
diff --git a/integration_tests/tests/auth_transfer/public.rs b/integration_tests/tests/auth_transfer/public.rs
index 69988d54..3f22efab 100644
--- a/integration_tests/tests/auth_transfer/public.rs
+++ b/integration_tests/tests/auth_transfer/public.rs
@@ -25,6 +25,7 @@ async fn successful_transfer_to_existing_account() -> Result<()> {
         to: Some(public_mention(ctx.existing_public_accounts()[1])),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -83,6 +84,7 @@ pub async fn successful_transfer_to_new_account() -> Result<()> {
         to: Some(public_mention(new_persistent_account_id)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -120,6 +122,7 @@ async fn failed_transfer_with_insufficient_balance() -> Result<()> {
         to: Some(public_mention(ctx.existing_public_accounts()[1])),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 1_000_000,
     });
@@ -159,6 +162,7 @@ async fn two_consecutive_successful_transfers() -> Result<()> {
         to: Some(public_mention(ctx.existing_public_accounts()[1])),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -192,6 +196,7 @@ async fn two_consecutive_successful_transfers() -> Result<()> {
         to: Some(public_mention(ctx.existing_public_accounts()[1])),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -274,6 +279,7 @@ async fn successful_transfer_using_from_label() -> Result<()> {
         to: Some(public_mention(ctx.existing_public_accounts()[1])),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -319,6 +325,7 @@ async fn successful_transfer_using_to_label() -> Result<()> {
         to: Some(CliAccountMention::Label(label)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
diff --git a/integration_tests/tests/indexer.rs b/integration_tests/tests/indexer.rs
index e3b3bc7b..c3de190c 100644
--- a/integration_tests/tests/indexer.rs
+++ b/integration_tests/tests/indexer.rs
@@ -115,6 +115,7 @@ async fn indexer_state_consistency() -> Result<()> {
         to: Some(public_mention(ctx.existing_public_accounts()[1])),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -150,6 +151,7 @@ async fn indexer_state_consistency() -> Result<()> {
         to: Some(private_mention(to)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -233,6 +235,7 @@ async fn indexer_state_consistency_with_labels() -> Result<()> {
         to: Some(CliAccountMention::Label(to_label)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
diff --git a/integration_tests/tests/indexer_ffi.rs b/integration_tests/tests/indexer_ffi.rs
index 8088b6cb..fb8d500f 100644
--- a/integration_tests/tests/indexer_ffi.rs
+++ b/integration_tests/tests/indexer_ffi.rs
@@ -195,6 +195,7 @@ fn indexer_ffi_state_consistency() -> Result<()> {
         to_npk: None,
         to_vpk: None,
         amount: 100,
+        to_keys: None,
         to_identifier: Some(0),
     });
 
@@ -234,6 +235,7 @@ fn indexer_ffi_state_consistency() -> Result<()> {
         to_npk: None,
         to_vpk: None,
         amount: 100,
+        to_keys: None,
         to_identifier: Some(0),
     });
 
@@ -345,6 +347,7 @@ fn indexer_ffi_state_consistency_with_labels() -> Result<()> {
         to_npk: None,
         to_vpk: None,
         amount: 100,
+        to_keys: None,
         to_identifier: Some(0),
     });
 
diff --git a/integration_tests/tests/keys.rs b/integration_tests/tests/keys.rs
index 0cc3c187..4c9b4521 100644
--- a/integration_tests/tests/keys.rs
+++ b/integration_tests/tests/keys.rs
@@ -71,7 +71,10 @@ async fn sync_private_account_with_non_zero_chain_index() -> Result<()> {
         from: private_mention(from),
         to: None,
         to_npk: Some(hex::encode(to_account.key_chain.nullifier_public_key.0)),
-        to_vpk: Some(hex::encode(&to_account.key_chain.viewing_public_key.0)),
+        to_vpk: Some(hex::encode(
+            to_account.key_chain.viewing_public_key.to_bytes(),
+        )),
+        to_keys: None,
         to_identifier: Some(to_account.kind.identifier()),
         amount: 100,
     });
@@ -147,6 +150,7 @@ async fn restore_keys_from_seed() -> Result<()> {
         to: Some(private_mention(to_account_id1)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 100,
     });
@@ -158,6 +162,7 @@ async fn restore_keys_from_seed() -> Result<()> {
         to: Some(private_mention(to_account_id2)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 101,
     });
@@ -197,6 +202,7 @@ async fn restore_keys_from_seed() -> Result<()> {
         to: Some(public_mention(to_account_id3)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 102,
     });
@@ -208,6 +214,7 @@ async fn restore_keys_from_seed() -> Result<()> {
         to: Some(public_mention(to_account_id4)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 103,
     });
@@ -268,6 +275,7 @@ async fn restore_keys_from_seed() -> Result<()> {
         to: Some(private_mention(to_account_id2)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 10,
     });
@@ -278,6 +286,7 @@ async fn restore_keys_from_seed() -> Result<()> {
         to: Some(public_mention(to_account_id4)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: 11,
     });
diff --git a/integration_tests/tests/private_pda.rs b/integration_tests/tests/private_pda.rs
index b0e3336e..0f219b2f 100644
--- a/integration_tests/tests/private_pda.rs
+++ b/integration_tests/tests/private_pda.rs
@@ -64,9 +64,9 @@ async fn fund_private_pda(
     let sender_pre = AccountWithMetadata::new(sender_account.clone(), true, sender);
     let pda_pre = AccountWithMetadata::new(Account::default(), false, pda_account_id);
 
-    let eph_holder = EphemeralKeyHolder::new(&npk);
-    let ssk = eph_holder.calculate_shared_secret_sender(&vpk);
-    let epk = eph_holder.generate_ephemeral_public_key();
+    let eph_holder = EphemeralKeyHolder::new(&vpk);
+    let ssk = eph_holder.calculate_shared_secret_sender();
+    let epk = eph_holder.ephemeral_public_key().clone();
 
     let instruction = Program::serialize_instruction(AuthTransferInstruction::Transfer { amount })
         .context("failed to serialize auth_transfer instruction")?;
@@ -272,10 +272,10 @@ async fn private_pda_family_members_receive_and_spend() -> Result<()> {
 
     // Fresh recipients — hardcoded npks not in any wallet.
     let recipient_npk_0 = NullifierPublicKey([0xAA; 32]);
-    let recipient_vpk_0 = ViewingPublicKey::from_scalar(recipient_npk_0.0);
+    let recipient_vpk_0 = ViewingPublicKey::from_seed(&[0_u8; 32], &[1_u8; 32]);
 
     let recipient_npk_1 = NullifierPublicKey([0xBB; 32]);
-    let recipient_vpk_1 = ViewingPublicKey::from_scalar(recipient_npk_1.0);
+    let recipient_vpk_1 = ViewingPublicKey::from_seed(&[2_u8; 32], &[3_u8; 32]);
 
     let amount_spend_0: u128 = 13;
     let amount_spend_1: u128 = 37;
diff --git a/integration_tests/tests/shared_accounts.rs b/integration_tests/tests/shared_accounts.rs
index aa1077ff..48207977 100644
--- a/integration_tests/tests/shared_accounts.rs
+++ b/integration_tests/tests/shared_accounts.rs
@@ -107,8 +107,11 @@ async fn group_invite_join_key_agreement() -> Result<()> {
         .key_chain()
         .sealing_secret_key()
         .context("Sealing key not found")?;
-    let sealing_pk =
-        key_protocol::key_management::group_key_holder::SealingPublicKey::from_scalar(sealing_sk);
+    let sealing_pk = key_protocol::key_management::group_key_holder::SealingPublicKey::from_bytes(
+        nssa_core::encryption::ViewingPublicKey::from_seed(&sealing_sk.d, &sealing_sk.z)
+            .to_bytes()
+            .to_vec(),
+    );
 
     let holder = ctx
         .wallet()
@@ -204,6 +207,7 @@ async fn fund_shared_account_from_public() -> Result<()> {
         to: Some(private_mention(shared_id)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: None,
         amount: 100,
     });
diff --git a/integration_tests/tests/token.rs b/integration_tests/tests/token.rs
index 65011976..943ef3b9 100644
--- a/integration_tests/tests/token.rs
+++ b/integration_tests/tests/token.rs
@@ -133,6 +133,7 @@ async fn create_and_transfer_public_token() -> Result<()> {
         to: Some(public_mention(recipient_account_id)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: transfer_amount,
     };
@@ -223,6 +224,7 @@ async fn create_and_transfer_public_token() -> Result<()> {
         holder: Some(public_mention(recipient_account_id)),
         holder_npk: None,
         holder_vpk: None,
+        holder_keys: None,
         holder_identifier: None,
         amount: mint_amount,
     };
@@ -365,6 +367,7 @@ async fn create_and_transfer_token_with_private_supply() -> Result<()> {
         to: Some(private_mention(recipient_account_id)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: transfer_amount,
     };
@@ -554,6 +557,7 @@ async fn create_token_with_private_definition() -> Result<()> {
         holder: Some(public_mention(recipient_account_id_public)),
         holder_npk: None,
         holder_vpk: None,
+        holder_keys: None,
         holder_identifier: None,
         amount: mint_amount_public,
     };
@@ -601,6 +605,7 @@ async fn create_token_with_private_definition() -> Result<()> {
         holder: Some(private_mention(recipient_account_id_private)),
         holder_npk: None,
         holder_vpk: None,
+        holder_keys: None,
         holder_identifier: None,
         amount: mint_amount_private,
     };
@@ -740,6 +745,7 @@ async fn create_token_with_private_definition_and_supply() -> Result<()> {
         to: Some(private_mention(recipient_account_id)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: transfer_amount,
     };
@@ -868,6 +874,7 @@ async fn shielded_token_transfer() -> Result<()> {
         to: Some(private_mention(recipient_account_id)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: transfer_amount,
     };
@@ -991,6 +998,7 @@ async fn deshielded_token_transfer() -> Result<()> {
         to: Some(public_mention(recipient_account_id)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: transfer_amount,
     };
@@ -1124,7 +1132,8 @@ async fn token_claiming_path_with_private_accounts() -> Result<()> {
         definition: private_mention(definition_account_id),
         holder: None,
         holder_npk: Some(hex::encode(holder_keys.nullifier_public_key.0)),
-        holder_vpk: Some(hex::encode(&holder_keys.viewing_public_key.0)),
+        holder_vpk: Some(hex::encode(holder_keys.viewing_public_key.to_bytes())),
+        holder_keys: None,
         holder_identifier: Some(holder_identifier),
         amount: mint_amount,
     };
@@ -1323,6 +1332,7 @@ async fn transfer_token_using_from_label() -> Result<()> {
         to: Some(public_mention(recipient_account_id)),
         to_npk: None,
         to_vpk: None,
+        to_keys: None,
         to_identifier: Some(0),
         amount: transfer_amount,
     };
diff --git a/integration_tests/tests/tps.rs b/integration_tests/tests/tps.rs
index 0a6a9038..0fb9b042 100644
--- a/integration_tests/tests/tps.rs
+++ b/integration_tests/tests/tps.rs
@@ -256,8 +256,7 @@ pub async fn tps_test() -> Result<()> {
 fn build_privacy_transaction() -> PrivacyPreservingTransaction {
     let program = Program::authenticated_transfer_program();
     let sender_nsk = [1; 32];
-    let sender_vsk = [99; 32];
-    let sender_vpk = ViewingPublicKey::from_scalar(sender_vsk);
+    let sender_vpk = ViewingPublicKey::from_seed(&[99_u8; 32], &[100_u8; 32]);
     let sender_npk = NullifierPublicKey::from(&sender_nsk);
     let sender_pre = AccountWithMetadata::new(
         Account {
@@ -270,8 +269,7 @@ fn build_privacy_transaction() -> PrivacyPreservingTransaction {
         AccountId::for_regular_private_account(&sender_npk, 0),
     );
     let recipient_nsk = [2; 32];
-    let recipient_vsk = [99; 32];
-    let recipient_vpk = ViewingPublicKey::from_scalar(recipient_vsk);
+    let recipient_vpk = ViewingPublicKey::from_seed(&[101_u8; 32], &[102_u8; 32]);
     let recipient_npk = NullifierPublicKey::from(&recipient_nsk);
     let recipient_pre = AccountWithMetadata::new(
         Account::default(),
@@ -279,13 +277,13 @@ fn build_privacy_transaction() -> PrivacyPreservingTransaction {
         AccountId::for_regular_private_account(&recipient_npk, 0),
     );
 
-    let eph_holder_from = EphemeralKeyHolder::new(&sender_npk);
-    let sender_ss = eph_holder_from.calculate_shared_secret_sender(&sender_vpk);
-    let sender_epk = eph_holder_from.generate_ephemeral_public_key();
+    let eph_holder_from = EphemeralKeyHolder::new(&sender_vpk);
+    let sender_ss = eph_holder_from.calculate_shared_secret_sender();
+    let sender_epk = eph_holder_from.ephemeral_public_key().clone();
 
-    let eph_holder_to = EphemeralKeyHolder::new(&recipient_npk);
-    let recipient_ss = eph_holder_to.calculate_shared_secret_sender(&recipient_vpk);
-    let recipient_epk = eph_holder_from.generate_ephemeral_public_key();
+    let eph_holder_to = EphemeralKeyHolder::new(&recipient_vpk);
+    let recipient_ss = eph_holder_to.calculate_shared_secret_sender();
+    let recipient_epk = eph_holder_to.ephemeral_public_key().clone();
 
     let balance_to_move: u128 = 1;
     let proof: MembershipProof = (
diff --git a/key_protocol/Cargo.toml b/key_protocol/Cargo.toml
index a0b5c397..dbb5624d 100644
--- a/key_protocol/Cargo.toml
+++ b/key_protocol/Cargo.toml
@@ -19,6 +19,7 @@ common.workspace = true
 anyhow.workspace = true
 serde.workspace = true
 k256.workspace = true
+ml-kem.workspace = true
 sha2.workspace = true
 rand.workspace = true
 hex.workspace = true
diff --git a/key_protocol/src/key_management/ephemeral_key_holder.rs b/key_protocol/src/key_management/ephemeral_key_holder.rs
index 7a6dc7d0..77797bc2 100644
--- a/key_protocol/src/key_management/ephemeral_key_holder.rs
+++ b/key_protocol/src/key_management/ephemeral_key_holder.rs
@@ -1,53 +1,61 @@
 use nssa_core::{
-    NullifierPublicKey, SharedSecretKey,
-    encryption::{EphemeralPublicKey, EphemeralSecretKey, ViewingPublicKey},
+    SharedSecretKey,
+    encryption::{EphemeralPublicKey, ViewingPublicKey},
 };
-use rand::{RngCore as _, rngs::OsRng};
-use sha2::Digest as _;
 
-#[derive(Debug)]
-/// Ephemeral secret key holder. Non-clonable as intended for one-time use. Produces ephemeral
-/// public keys. Can produce shared secret for sender.
+/// Ephemeral key holder for the sender side of a KEM-based shared-secret exchange.
+///
+/// Non-clonable as intended for one-time use: construction encapsulates once and
+/// stores both the shared secret and the ciphertext (`EphemeralPublicKey`) that must
+/// be sent to the receiver.
 pub struct EphemeralKeyHolder {
-    ephemeral_secret_key: EphemeralSecretKey,
+    shared_secret: SharedSecretKey,
+    ephemeral_public_key: EphemeralPublicKey,
+}
+
+// SharedSecretKey does not implement Debug (intentional — leaking key material via
+// debug output would be a security risk). We implement Debug manually here, redacting the
+// shared secret while still allowing the ephemeral public key (KEM ciphertext) to be inspected.
+impl std::fmt::Debug for EphemeralKeyHolder {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("EphemeralKeyHolder")
+            .field("shared_secret", &"<redacted>")
+            .field("ephemeral_public_key", &self.ephemeral_public_key)
+            .finish()
+    }
 }
 
 impl EphemeralKeyHolder {
     #[must_use]
-    pub fn new(receiver_nullifier_public_key: &NullifierPublicKey) -> Self {
-        let mut nonce_bytes = [0; 16];
-        OsRng.fill_bytes(&mut nonce_bytes);
-        let mut hasher = sha2::Sha256::new();
-        hasher.update(receiver_nullifier_public_key);
-        hasher.update(nonce_bytes);
-
+    pub fn new(receiver_viewing_public_key: &ViewingPublicKey) -> Self {
+        let (shared_secret, ephemeral_public_key) =
+            SharedSecretKey::encapsulate(receiver_viewing_public_key);
         Self {
-            ephemeral_secret_key: hasher.finalize().into(),
+            shared_secret,
+            ephemeral_public_key,
         }
     }
 
+    /// Returns the KEM ciphertext to be transmitted to the receiver as the `EphemeralPublicKey`.
     #[must_use]
-    pub fn generate_ephemeral_public_key(&self) -> EphemeralPublicKey {
-        EphemeralPublicKey::from_scalar(self.ephemeral_secret_key)
+    pub const fn ephemeral_public_key(&self) -> &EphemeralPublicKey {
+        &self.ephemeral_public_key
     }
 
+    /// Returns the sender-side shared secret (established at construction time).
     #[must_use]
-    pub fn calculate_shared_secret_sender(
-        &self,
-        receiver_viewing_public_key: &ViewingPublicKey,
-    ) -> SharedSecretKey {
-        SharedSecretKey::new(self.ephemeral_secret_key, receiver_viewing_public_key)
+    pub const fn calculate_shared_secret_sender(&self) -> SharedSecretKey {
+        self.shared_secret
     }
 }
 
+/// Encapsulates a fresh shared secret toward `vpk` and returns `(shared_secret, ciphertext)`.
+///
+/// Used when the local side is acting as an "ephemeral receiver" — i.e. generating a
+/// one-sided encryption that only the holder of the VSK can decrypt.
 #[must_use]
 pub fn produce_one_sided_shared_secret_receiver(
     vpk: &ViewingPublicKey,
 ) -> (SharedSecretKey, EphemeralPublicKey) {
-    let mut esk = [0; 32];
-    OsRng.fill_bytes(&mut esk);
-    (
-        SharedSecretKey::new(esk, vpk),
-        EphemeralPublicKey::from_scalar(esk),
-    )
+    SharedSecretKey::encapsulate(vpk)
 }
diff --git a/key_protocol/src/key_management/group_key_holder.rs b/key_protocol/src/key_management/group_key_holder.rs
index 39a3fd19..656d9e36 100644
--- a/key_protocol/src/key_management/group_key_holder.rs
+++ b/key_protocol/src/key_management/group_key_holder.rs
@@ -1,44 +1,39 @@
 use aes_gcm::{Aes256Gcm, KeyInit as _, aead::Aead as _};
 use nssa_core::{
     SharedSecretKey,
-    encryption::{Scalar, shared_key_derivation::Secp256k1Point},
+    encryption::{EphemeralPublicKey, MlKem768EncapsulationKey},
     program::{PdaSeed, ProgramId},
 };
 use rand::{RngCore as _, rngs::OsRng};
 use serde::{Deserialize, Serialize};
 use sha2::{Digest as _, digest::FixedOutput as _};
 
-use super::secret_holders::{PrivateKeyHolder, SecretSpendingKey};
+use super::secret_holders::{PrivateKeyHolder, SecretSpendingKey, ViewingSecretKey};
 
 /// Public key used to seal a `GroupKeyHolder` for distribution to a recipient.
 ///
-/// Wraps a secp256k1 point but is a distinct type from `ViewingPublicKey` to enforce
-/// key separation: viewing keys encrypt account state, sealing keys encrypt the GMS
-/// for off-chain distribution.
-pub struct SealingPublicKey(Secp256k1Point);
+/// Wraps the ML-KEM-768 encapsulation key bytes (1184 bytes). Distinct from
+/// `ViewingPublicKey` to enforce key separation: viewing keys encrypt account state,
+/// sealing keys encrypt the GMS for off-chain distribution.
+pub struct SealingPublicKey(Vec<u8>);
 
 impl SealingPublicKey {
-    /// Derive the sealing public key from a secret scalar.
-    #[must_use]
-    pub fn from_scalar(scalar: Scalar) -> Self {
-        Self(Secp256k1Point::from_scalar(scalar))
-    }
-
-    /// Construct from raw serialized bytes (e.g. received from another wallet).
+    /// Construct from raw serialized encapsulation-key bytes (e.g. received from another wallet).
     #[must_use]
     pub const fn from_bytes(bytes: Vec<u8>) -> Self {
-        Self(Secp256k1Point(bytes))
+        Self(bytes)
     }
 
     /// Returns the raw bytes for display or transmission.
     #[must_use]
     pub fn to_bytes(&self) -> &[u8] {
-        &self.0.0
+        &self.0
     }
 }
 
 /// Secret key used to unseal a `GroupKeyHolder` received from another member.
-pub type SealingSecretKey = Scalar;
+/// Holds the two 32-byte FIPS 203 seed halves `d` and `z`.
+pub type SealingSecretKey = ViewingSecretKey;
 
 /// Manages shared viewing keys for a group of controllers owning private PDAs.
 ///
@@ -153,18 +148,17 @@ impl GroupKeyHolder {
 
     /// Encrypts this holder's GMS under the recipient's [`SealingPublicKey`].
     ///
-    /// Uses an ephemeral ECDH key exchange to derive a shared secret, then AES-256-GCM
-    /// to encrypt the payload. The returned bytes are
-    /// `ephemeral_pubkey (33) || nonce (12) || ciphertext+tag (48)` = 93 bytes.
+    /// Uses ML-KEM-768 encapsulation to derive a shared secret, then AES-256-GCM to encrypt
+    /// the payload. The returned bytes are
+    /// `kem_ciphertext (1088) || nonce (12) || ciphertext+tag (48)` = 1148 bytes.
     ///
-    /// Each call generates a fresh ephemeral key, so two seals of the same holder produce
+    /// Each call generates a fresh KEM encapsulation, so two seals of the same holder produce
     /// different ciphertexts.
     #[must_use]
     pub fn seal_for(&self, recipient_key: &SealingPublicKey) -> Vec<u8> {
-        let mut ephemeral_scalar: Scalar = [0_u8; 32];
-        OsRng.fill_bytes(&mut ephemeral_scalar);
-        let ephemeral_pubkey = Secp256k1Point::from_scalar(ephemeral_scalar);
-        let shared = SharedSecretKey::new(ephemeral_scalar, &recipient_key.0);
+        let sealing_key = MlKem768EncapsulationKey::from_bytes(recipient_key.0.clone())
+            .expect("key_protocol::group_key_holder::GroupKeyHolder::seal_for: SealingPublicKey must be a valid ML-KEM-768 encapsulation key");
+        let (shared, kem_ct) = SharedSecretKey::encapsulate(&sealing_key);
         let aes_key = Self::seal_kdf(&shared);
         let cipher = Aes256Gcm::new(&aes_key.into());
 
@@ -176,12 +170,12 @@ impl GroupKeyHolder {
             .encrypt(&nonce, self.gms.as_ref())
             .expect("AES-GCM encryption should not fail with valid key/nonce");
 
-        let capacity = 33_usize
+        let capacity = 1088_usize
             .checked_add(12)
             .and_then(|n| n.checked_add(ciphertext.len()))
             .expect("seal capacity overflow");
         let mut out = Vec::with_capacity(capacity);
-        out.extend_from_slice(&ephemeral_pubkey.0);
+        out.extend_from_slice(&kem_ct.0);
         out.extend_from_slice(&nonce_bytes);
         out.extend_from_slice(&ciphertext);
         out
@@ -189,20 +183,24 @@ impl GroupKeyHolder {
 
     /// Decrypts a sealed `GroupKeyHolder` using the recipient's [`SealingSecretKey`].
     ///
-    /// Returns `Err` if the ciphertext is too short, the ECDH point is invalid, or the
-    /// AES-GCM authentication tag doesn't verify (wrong key or tampered data).
-    pub fn unseal(sealed: &[u8], own_key: SealingSecretKey) -> Result<Self, SealError> {
-        const HEADER_LEN: usize = 33 + 12;
+    /// Returns `Err` if the ciphertext is too short or the AES-GCM authentication tag
+    /// doesn't verify (wrong key or tampered data).
+    pub fn unseal(sealed: &[u8], own_key: &SealingSecretKey) -> Result<Self, SealError> {
+        // kem_ciphertext (1088) + nonce (12) = header, then AES-GCM tag (16) minimum.
+        const KEM_CT_LEN: usize = 1088;
+        const HEADER_LEN: usize = KEM_CT_LEN + 12;
         const MIN_LEN: usize = HEADER_LEN + 16;
+
         if sealed.len() < MIN_LEN {
             return Err(SealError::TooShort);
         }
-        // MIN_LEN (61) > HEADER_LEN (45), so all slicing below is in bounds.
-        let ephemeral_pubkey = Secp256k1Point(sealed[..33].to_vec());
-        let nonce = aes_gcm::Nonce::from_slice(&sealed[33..HEADER_LEN]);
+
+        let kem_ct = EphemeralPublicKey(sealed[..KEM_CT_LEN].to_vec());
+        let nonce = aes_gcm::Nonce::from_slice(&sealed[KEM_CT_LEN..HEADER_LEN]);
         let ciphertext = &sealed[HEADER_LEN..];
 
-        let shared = SharedSecretKey::new(own_key, &ephemeral_pubkey);
+        let shared = SharedSecretKey::decapsulate(&kem_ct, &own_key.d, &own_key.z)
+            .expect("key_protocol::group_key_holder::GroupKeyHolder::unseal: KEM_CT_LEN guarantees exactly 1088 bytes");
         let aes_key = Self::seal_kdf(&shared);
         let cipher = Aes256Gcm::new(&aes_key.into());
 
@@ -219,7 +217,7 @@ impl GroupKeyHolder {
         Ok(Self::from_gms(gms))
     }
 
-    /// Derives an AES-256 key from the ECDH shared secret via SHA-256 with a domain prefix.
+    /// Derives an AES-256 key from the ML-KEM shared secret via SHA-256 with a domain prefix.
     fn seal_kdf(shared: &SharedSecretKey) -> [u8; 32] {
         const PREFIX: &[u8; 32] = b"/LEE/v0.3/GroupKeySeal/AES\x00\x00\x00\x00\x00\x00";
         let mut hasher = sha2::Sha256::new();
@@ -407,8 +405,10 @@ mod tests {
         let recipient_vpk = recipient_keys.generate_viewing_public_key();
         let recipient_vsk = recipient_keys.viewing_secret_key;
 
-        let sealed = holder.seal_for(&SealingPublicKey::from_bytes(recipient_vpk.0));
-        let restored = GroupKeyHolder::unseal(&sealed, recipient_vsk).expect("unseal");
+        let sealed = holder.seal_for(&SealingPublicKey::from_bytes(
+            recipient_vpk.to_bytes().to_vec(),
+        ));
+        let restored = GroupKeyHolder::unseal(&sealed, &recipient_vsk).expect("unseal");
 
         assert_eq!(restored.dangerous_raw_gms(), holder.dangerous_raw_gms());
 
@@ -433,13 +433,14 @@ mod tests {
             .produce_private_key_holder(None)
             .generate_viewing_public_key();
 
-        let wrong_ssk = SecretSpendingKey([99_u8; 32]);
-        let wrong_vsk = wrong_ssk
+        let wrong_vsk = SecretSpendingKey([99_u8; 32])
             .produce_private_key_holder(None)
             .viewing_secret_key;
 
-        let sealed = holder.seal_for(&SealingPublicKey::from_bytes(recipient_vpk.0));
-        let result = GroupKeyHolder::unseal(&sealed, wrong_vsk);
+        let sealed = holder.seal_for(&SealingPublicKey::from_bytes(
+            recipient_vpk.to_bytes().to_vec(),
+        ));
+        let result = GroupKeyHolder::unseal(&sealed, &wrong_vsk);
         assert!(matches!(result, Err(super::SealError::DecryptionFailed)));
     }
 
@@ -453,16 +454,18 @@ mod tests {
         let recipient_vpk = recipient_keys.generate_viewing_public_key();
         let recipient_vsk = recipient_keys.viewing_secret_key;
 
-        let mut sealed = holder.seal_for(&SealingPublicKey::from_bytes(recipient_vpk.0));
-        // Flip a byte in the ciphertext portion (after ephemeral_pubkey + nonce)
+        let mut sealed = holder.seal_for(&SealingPublicKey::from_bytes(
+            recipient_vpk.to_bytes().to_vec(),
+        ));
+        // Flip a byte in the AES-GCM ciphertext portion (after KEM ciphertext + nonce).
         let last = sealed.len() - 1;
         sealed[last] ^= 0xFF;
 
-        let result = GroupKeyHolder::unseal(&sealed, recipient_vsk);
+        let result = GroupKeyHolder::unseal(&sealed, &recipient_vsk);
         assert!(matches!(result, Err(super::SealError::DecryptionFailed)));
     }
 
-    /// Two seals of the same holder produce different ciphertexts (ephemeral randomness).
+    /// Two seals of the same holder produce different ciphertexts (KEM randomness).
     #[test]
     fn two_seals_produce_different_ciphertexts() {
         let holder = GroupKeyHolder::from_gms([42_u8; 32]);
@@ -472,7 +475,7 @@ mod tests {
             .produce_private_key_holder(None)
             .generate_viewing_public_key();
 
-        let sealing_key = SealingPublicKey::from_bytes(recipient_vpk.0);
+        let sealing_key = SealingPublicKey::from_bytes(recipient_vpk.to_bytes().to_vec());
         let sealed_a = holder.seal_for(&sealing_key);
         let sealed_b = holder.seal_for(&sealing_key);
         assert_ne!(sealed_a, sealed_b);
@@ -481,14 +484,15 @@ mod tests {
     /// Sealed payload is too short.
     #[test]
     fn unseal_too_short_fails() {
-        let vsk: SealingSecretKey = [7_u8; 32];
-        let result = GroupKeyHolder::unseal(&[0_u8; 10], vsk);
+        let vsk = SealingSecretKey {
+            d: [7_u8; 32],
+            z: [0_u8; 32],
+        };
+        let result = GroupKeyHolder::unseal(&[0_u8; 10], &vsk);
         assert!(matches!(result, Err(super::SealError::TooShort)));
     }
 
-    /// Degenerate GMS values (all-zeros, all-ones, single-bit) must still produce valid,
-    /// non-zero, pairwise-distinct npks. Rules out accidental "if gms == default { return
-    /// default }" style shortcuts in the derivation.
+    /// Degenerate GMS values must still produce valid, non-zero, pairwise-distinct npks.
     #[test]
     fn degenerate_gms_produces_distinct_non_zero_keys() {
         let seed = PdaSeed::new([1; 32]);
@@ -526,21 +530,19 @@ mod tests {
         let pda_seed = PdaSeed::new([42_u8; 32]);
         let program_id: nssa_core::program::ProgramId = [1; 8];
 
-        // Derive Alice's keys
         let alice_keys = alice_holder.derive_keys_for_pda(&TEST_PROGRAM_ID, &pda_seed);
         let alice_npk = alice_keys.generate_nullifier_public_key();
 
-        // Seal GMS for Bob using Bob's viewing key, Bob unseals
         let bob_ssk = SecretSpendingKey([77_u8; 32]);
         let bob_keys = bob_ssk.produce_private_key_holder(None);
         let bob_vpk = bob_keys.generate_viewing_public_key();
         let bob_vsk = bob_keys.viewing_secret_key;
 
-        let sealed = alice_holder.seal_for(&SealingPublicKey::from_bytes(bob_vpk.0));
+        let sealed =
+            alice_holder.seal_for(&SealingPublicKey::from_bytes(bob_vpk.to_bytes().to_vec()));
         let bob_holder =
-            GroupKeyHolder::unseal(&sealed, bob_vsk).expect("Bob should unseal the GMS");
+            GroupKeyHolder::unseal(&sealed, &bob_vsk).expect("Bob should unseal the GMS");
 
-        // Key agreement: both derive identical NPK and AccountId
         let bob_npk = bob_holder
             .derive_keys_for_pda(&TEST_PROGRAM_ID, &pda_seed)
             .generate_nullifier_public_key();
diff --git a/key_protocol/src/key_management/key_tree/keys_private.rs b/key_protocol/src/key_management/key_tree/keys_private.rs
index ab4c5c29..cb324897 100644
--- a/key_protocol/src/key_management/key_tree/keys_private.rs
+++ b/key_protocol/src/key_management/key_tree/keys_private.rs
@@ -1,8 +1,8 @@
 use std::collections::BTreeMap;
 
-use k256::{Scalar, elliptic_curve::PrimeField as _};
-use nssa_core::{NullifierPublicKey, PrivateAccountKind, encryption::ViewingPublicKey};
+use nssa_core::{NullifierPublicKey, PrivateAccountKind, encryption::MlKem768EncapsulationKey};
 use serde::{Deserialize, Serialize};
+use sha2::Digest as _;
 
 use crate::key_management::{
     KeyChain,
@@ -34,10 +34,10 @@ impl ChildKeysPrivate {
             .expect("hash_value is 64 bytes, must be safe to get last 32");
 
         let nsk = ssk.generate_nullifier_secret_key(None);
-        let vsk = ssk.generate_viewing_secret_key(None);
+        let vsk = ssk.generate_viewing_secret_seed_key(None);
 
         let npk = NullifierPublicKey::from(&nsk);
-        let vpk = ViewingPublicKey::from_scalar(vsk);
+        let vpk = MlKem768EncapsulationKey::from(&vsk);
 
         Self {
             value: (
@@ -59,16 +59,20 @@ impl ChildKeysPrivate {
 
     #[must_use]
     pub fn nth_child(&self, cci: u32) -> Self {
-        #[expect(clippy::arithmetic_side_effects, reason = "TODO: fix later")]
-        let parent_pt =
-            Scalar::from_repr(self.value.0.private_key_holder.nullifier_secret_key.into())
-                .expect("Key generated as scalar, must be valid representation")
-                * Scalar::from_repr(self.value.0.private_key_holder.viewing_secret_key.into())
-                    .expect("Key generated as scalar, must be valid representation");
-        let mut input = vec![];
+        // `parent_hash`` is used to incorporate entropy based on the parent node's keys
+        // to generate the `ssk` and `ccc` values.
+        let mut parent_hash = sha2::Sha256::new();
+        parent_hash.update(b"LEE/keys");
+        parent_hash.update(self.value.0.private_key_holder.nullifier_secret_key);
+        parent_hash.update(self.value.0.private_key_holder.viewing_secret_key.d);
+        parent_hash.update(self.value.0.private_key_holder.viewing_secret_key.z);
+        let parent_pt = parent_hash.finalize();
 
+        // Each child (of the same parent node) share the same `parent_pt`.
+        // To ensure that each child generates unique keys, we include the child index.
+        let mut input = vec![];
         input.extend_from_slice(b"LEE_seed_priv");
-        input.extend_from_slice(&parent_pt.to_bytes());
+        input.extend_from_slice(&parent_pt);
         #[expect(clippy::big_endian_bytes, reason = "BIP-032 uses big endian")]
         input.extend_from_slice(&cci.to_be_bytes());
 
@@ -84,10 +88,10 @@ impl ChildKeysPrivate {
             .expect("hash_value is 64 bytes, must be safe to get last 32");
 
         let nsk = ssk.generate_nullifier_secret_key(Some(cci));
-        let vsk = ssk.generate_viewing_secret_key(Some(cci));
+        let vsk = ssk.generate_viewing_secret_seed_key(Some(cci));
 
         let npk = NullifierPublicKey::from(&nsk);
-        let vpk = ViewingPublicKey::from_scalar(vsk);
+        let vpk = MlKem768EncapsulationKey::from(&vsk);
 
         Self {
             value: (
@@ -128,12 +132,11 @@ impl KeyTreeNode for ChildKeysPrivate {
 
 #[cfg(test)]
 mod tests {
-    use nssa_core::{NullifierPublicKey, NullifierSecretKey};
+    use nssa_core::NullifierSecretKey;
 
     use super::*;
     use crate::key_management::{self, secret_holders::ViewingSecretKey};
 
-    #[expect(clippy::redundant_type_annotations, reason = "TODO: clippy requires")]
     #[test]
     fn master_key_generation() {
         let seed: [u8; 64] = [
@@ -145,7 +148,7 @@ mod tests {
 
         let keys = ChildKeysPrivate::root(seed);
 
-        let expected_ssk: SecretSpendingKey = key_management::secret_holders::SecretSpendingKey([
+        let expected_ssk = key_management::secret_holders::SecretSpendingKey([
             246, 79, 26, 124, 135, 95, 52, 51, 201, 27, 48, 194, 2, 144, 51, 219, 245, 128, 139,
             222, 42, 195, 105, 33, 115, 97, 186, 0, 97, 14, 218, 191,
         ]);
@@ -160,26 +163,92 @@ mod tests {
             34, 234, 19, 222, 2, 22, 12, 163, 252, 88, 11, 0, 163,
         ];
 
-        let expected_npk: NullifierPublicKey = nssa_core::NullifierPublicKey([
+        let expected_npk = nssa_core::NullifierPublicKey([
             7, 123, 125, 191, 233, 183, 201, 4, 20, 214, 155, 210, 45, 234, 27, 240, 194, 111, 97,
             247, 155, 113, 122, 246, 192, 0, 70, 61, 76, 71, 70, 2,
         ]);
-        let expected_vsk = [
-            155, 90, 54, 75, 228, 130, 68, 201, 129, 251, 180, 195, 250, 64, 34, 230, 241, 204,
-            216, 50, 149, 156, 10, 67, 208, 74, 9, 10, 47, 59, 50, 202,
-        ];
 
-        let expected_vpk_as_bytes: [u8; 33] = [
-            2, 191, 99, 102, 114, 40, 131, 109, 166, 8, 222, 186, 107, 29, 156, 106, 206, 96, 127,
-            80, 170, 66, 217, 79, 38, 80, 11, 74, 147, 123, 221, 159, 166,
-        ];
+        let expected_vsk = ViewingSecretKey::new(
+            [
+                187, 143, 146, 12, 68, 148, 25, 203, 21, 92, 131, 2, 221, 81, 117, 62, 98, 194,
+                159, 177, 102, 254, 236, 182, 76, 242, 116, 219, 17, 166, 99, 36,
+            ],
+            [
+                80, 97, 83, 209, 145, 99, 168, 99, 89, 29, 153, 236, 82, 99, 134, 114, 168, 19,
+                223, 69, 34, 47, 76, 76, 15, 97, 245, 184, 25, 103, 251, 82,
+            ],
+        );
 
+        let expected_vpk: [u8; 1184] = [
+            127, 229, 162, 212, 104, 117, 4, 150, 192, 103, 122, 195, 14, 35, 12, 60, 52, 23, 220,
+            150, 100, 203, 34, 34, 127, 232, 156, 43, 218, 109, 6, 160, 67, 35, 210, 194, 25, 181,
+            118, 237, 25, 129, 51, 160, 189, 51, 99, 184, 57, 28, 121, 240, 236, 2, 170, 198, 26,
+            91, 172, 110, 52, 32, 186, 35, 179, 202, 234, 249, 15, 242, 100, 198, 168, 163, 120,
+            205, 118, 85, 195, 210, 187, 95, 150, 154, 8, 68, 165, 237, 87, 166, 101, 57, 4, 18,
+            11, 122, 235, 180, 199, 154, 165, 158, 55, 136, 30, 237, 43, 167, 215, 68, 80, 102, 0,
+            71, 90, 130, 206, 240, 215, 69, 199, 83, 7, 60, 184, 128, 230, 184, 61, 93, 201, 204,
+            165, 104, 9, 127, 220, 52, 246, 217, 131, 251, 2, 170, 133, 6, 51, 40, 224, 101, 61,
+            16, 135, 32, 182, 201, 68, 58, 171, 54, 161, 184, 243, 38, 106, 200, 251, 17, 172, 8,
+            24, 73, 230, 55, 85, 20, 147, 222, 165, 200, 116, 135, 47, 20, 227, 56, 220, 64, 120,
+            215, 245, 58, 86, 102, 149, 252, 193, 163, 160, 59, 82, 138, 249, 171, 1, 54, 199, 193,
+            171, 85, 38, 64, 56, 121, 106, 84, 57, 252, 94, 147, 16, 191, 196, 104, 47, 129, 84,
+            21, 252, 160, 81, 207, 184, 199, 3, 177, 74, 117, 115, 175, 138, 108, 36, 198, 5, 32,
+            15, 218, 3, 20, 19, 15, 251, 209, 86, 128, 139, 148, 78, 10, 34, 144, 149, 74, 102, 48,
+            59, 70, 124, 47, 193, 100, 26, 9, 104, 178, 102, 156, 199, 242, 101, 147, 161, 87, 27,
+            234, 192, 204, 41, 36, 43, 83, 219, 15, 211, 66, 91, 76, 73, 13, 113, 155, 203, 193,
+            160, 130, 84, 103, 47, 70, 100, 147, 169, 65, 119, 84, 121, 122, 161, 76, 203, 144,
+            248, 145, 22, 8, 46, 121, 44, 77, 20, 149, 66, 179, 56, 149, 231, 98, 184, 9, 64, 14,
+            67, 196, 34, 8, 123, 21, 80, 169, 168, 223, 230, 133, 0, 66, 159, 230, 69, 201, 205,
+            169, 105, 196, 21, 71, 84, 70, 58, 165, 165, 134, 186, 232, 60, 70, 51, 57, 239, 74,
+            174, 116, 234, 36, 178, 49, 42, 168, 250, 104, 141, 106, 0, 109, 52, 86, 104, 243, 62,
+            214, 137, 48, 107, 2, 152, 206, 227, 175, 147, 236, 19, 113, 27, 191, 231, 235, 167,
+            114, 104, 23, 126, 203, 94, 242, 149, 171, 115, 170, 89, 244, 58, 29, 176, 73, 203, 44,
+            8, 32, 9, 226, 32, 78, 246, 38, 235, 149, 133, 25, 243, 47, 124, 180, 200, 211, 165,
+            137, 56, 169, 117, 31, 244, 65, 91, 135, 146, 158, 20, 75, 102, 32, 65, 250, 103, 199,
+            36, 48, 31, 155, 164, 191, 222, 85, 37, 66, 243, 17, 120, 104, 0, 228, 83, 200, 116, 6,
+            199, 106, 236, 139, 246, 216, 152, 241, 211, 85, 106, 200, 44, 231, 240, 66, 3, 193,
+            147, 16, 145, 65, 49, 33, 53, 247, 69, 47, 44, 113, 86, 117, 6, 20, 193, 183, 128, 178,
+            181, 21, 251, 99, 39, 149, 210, 146, 106, 181, 186, 7, 36, 63, 186, 234, 191, 164, 193,
+            162, 127, 250, 122, 189, 219, 21, 92, 48, 86, 209, 184, 99, 160, 201, 162, 145, 20,
+            138, 154, 18, 37, 180, 209, 165, 165, 51, 187, 78, 193, 175, 135, 6, 55, 216, 178, 10,
+            40, 246, 98, 128, 80, 14, 38, 69, 113, 123, 54, 94, 43, 50, 106, 167, 17, 77, 163, 148,
+            117, 225, 9, 7, 253, 240, 157, 96, 103, 33, 100, 37, 37, 20, 53, 138, 234, 55, 45, 232,
+            154, 9, 150, 192, 116, 36, 119, 106, 95, 119, 34, 220, 84, 174, 19, 227, 33, 209, 96,
+            197, 148, 230, 197, 59, 117, 130, 7, 116, 11, 0, 197, 16, 249, 151, 31, 4, 64, 29, 165,
+            247, 110, 176, 166, 4, 112, 136, 101, 208, 7, 179, 38, 183, 134, 58, 107, 207, 160, 38,
+            159, 67, 112, 20, 225, 199, 179, 133, 117, 144, 54, 199, 15, 204, 80, 154, 116, 84, 88,
+            109, 113, 5, 207, 226, 21, 62, 247, 122, 14, 156, 9, 8, 76, 26, 148, 67, 196, 128, 176,
+            78, 51, 161, 151, 75, 248, 154, 31, 168, 9, 4, 3, 107, 222, 245, 178, 21, 84, 7, 25,
+            155, 118, 97, 135, 63, 89, 233, 11, 207, 148, 155, 38, 106, 104, 102, 140, 104, 67,
+            149, 20, 30, 196, 44, 197, 128, 34, 182, 80, 30, 32, 137, 34, 212, 164, 177, 164, 12,
+            115, 41, 156, 111, 71, 230, 120, 111, 218, 25, 117, 218, 75, 167, 32, 37, 57, 50, 99,
+            181, 203, 40, 105, 248, 150, 114, 121, 73, 127, 198, 191, 161, 44, 56, 213, 243, 71, 2,
+            56, 192, 243, 107, 179, 27, 96, 21, 116, 169, 64, 15, 97, 166, 151, 200, 11, 40, 204,
+            71, 168, 220, 9, 55, 43, 146, 244, 212, 166, 192, 180, 189, 237, 162, 42, 29, 33, 52,
+            193, 4, 178, 157, 244, 28, 209, 44, 26, 36, 147, 126, 94, 164, 37, 47, 115, 38, 23,
+            165, 96, 106, 140, 42, 69, 146, 194, 93, 71, 175, 49, 147, 32, 246, 97, 94, 41, 116,
+            127, 174, 18, 16, 14, 163, 17, 180, 213, 203, 166, 33, 139, 214, 18, 170, 27, 41, 59,
+            175, 200, 101, 14, 128, 45, 179, 167, 136, 232, 138, 56, 124, 145, 75, 233, 132, 161,
+            196, 164, 72, 80, 60, 187, 38, 90, 90, 17, 66, 134, 59, 2, 165, 29, 76, 24, 38, 211,
+            177, 83, 119, 20, 239, 59, 77, 34, 3, 42, 47, 60, 89, 46, 103, 168, 120, 17, 199, 50,
+            17, 103, 107, 48, 8, 53, 220, 159, 212, 65, 198, 80, 8, 11, 235, 97, 203, 196, 240, 44,
+            56, 121, 77, 91, 196, 160, 129, 242, 149, 226, 57, 106, 180, 76, 161, 203, 18, 37, 166,
+            153, 44, 40, 28, 74, 8, 11, 6, 166, 54, 10, 103, 247, 23, 35, 7, 47, 173, 133, 71, 85,
+            3, 168, 250, 120, 126, 174, 37, 80, 128, 107, 7, 161, 130, 155, 136, 92, 48, 215, 119,
+            196, 124, 85, 157, 234, 2, 166, 137, 65, 121, 222, 112, 47, 17, 43, 23, 111, 88, 5,
+            195, 41, 8, 191, 227, 21, 173, 35, 199, 196, 188, 162, 191, 195, 204, 137, 54, 16, 73,
+            178, 150, 249, 234, 22, 216, 123, 157, 144, 218, 118, 53, 193, 67, 65, 84, 162, 244,
+            165, 24, 110, 246, 146, 228, 212, 180, 150, 116, 201, 37, 128, 76, 41, 188, 42, 79,
+            148, 52, 196, 176, 178, 224, 48, 168, 13, 129, 193, 131, 185, 131, 93, 40, 145, 56,
+            180, 29, 153, 83, 39, 69, 232, 96, 238, 137, 104, 150, 2, 202, 239, 149, 248, 154, 115,
+            115, 127, 3, 8, 32, 61, 96, 66, 25, 181, 14, 72, 73, 97, 186, 134, 140, 33, 69, 33, 74,
+        ];
         assert!(expected_ssk == keys.value.0.secret_spending_key);
         assert!(expected_ccc == keys.ccc);
         assert!(expected_nsk == keys.value.0.private_key_holder.nullifier_secret_key);
         assert!(expected_npk == keys.value.0.nullifier_public_key);
         assert!(expected_vsk == keys.value.0.private_key_holder.viewing_secret_key);
-        assert!(expected_vpk_as_bytes == keys.value.0.viewing_public_key.to_bytes());
+        assert!(expected_vpk == keys.value.0.viewing_public_key.to_bytes());
     }
 
     #[test]
@@ -194,33 +263,107 @@ mod tests {
         let root_node = ChildKeysPrivate::root(seed);
         let child_node = ChildKeysPrivate::nth_child(&root_node, 42_u32);
 
-        let expected_ccc: [u8; 32] = [
-            27, 73, 133, 213, 214, 63, 217, 184, 164, 17, 172, 140, 223, 95, 255, 157, 11, 0, 58,
-            53, 82, 147, 121, 120, 199, 50, 30, 28, 103, 24, 121, 187,
+        let expected_ssk = key_management::secret_holders::SecretSpendingKey([
+            215, 207, 70, 52, 161, 220, 88, 88, 241, 149, 81, 130, 217, 214, 252, 170, 51, 232,
+            230, 158, 195, 173, 174, 37, 27, 101, 49, 35, 79, 13, 44, 225,
+        ]);
+
+        let expected_ccc = [
+            113, 136, 96, 232, 12, 136, 185, 254, 36, 103, 64, 44, 238, 176, 240, 92, 219, 184,
+            143, 35, 183, 54, 170, 15, 126, 56, 115, 21, 89, 142, 236, 217,
         ];
 
         let expected_nsk: NullifierSecretKey = [
-            124, 61, 40, 92, 33, 135, 3, 41, 200, 234, 3, 69, 102, 184, 57, 191, 106, 151, 194,
-            192, 103, 132, 141, 112, 249, 108, 192, 117, 24, 48, 70, 216,
+            27, 167, 3, 140, 113, 16, 209, 83, 21, 77, 65, 91, 26, 191, 203, 102, 66, 140, 157,
+            220, 101, 104, 227, 135, 216, 215, 216, 126, 194, 196, 43, 34,
         ];
         let expected_npk = nssa_core::NullifierPublicKey([
-            116, 231, 246, 189, 145, 240, 37, 59, 219, 223, 216, 246, 116, 171, 223, 55, 197, 200,
-            134, 192, 221, 40, 218, 167, 239, 5, 11, 95, 147, 247, 162, 226,
+            30, 208, 29, 96, 156, 95, 79, 16, 182, 0, 10, 194, 209, 90, 35, 177, 110, 224, 247, 67,
+            219, 114, 113, 16, 42, 27, 220, 96, 151, 124, 8, 65,
         ]);
 
-        let expected_vsk: ViewingSecretKey = [
-            33, 155, 68, 60, 102, 70, 47, 105, 194, 129, 44, 26, 143, 198, 44, 244, 185, 31, 236,
-            252, 205, 89, 138, 107, 39, 38, 154, 73, 109, 166, 41, 114,
-        ];
-        let expected_vpk_as_bytes: [u8; 33] = [
-            2, 78, 213, 113, 117, 105, 162, 248, 175, 68, 128, 232, 106, 204, 208, 159, 11, 78, 48,
-            244, 127, 112, 46, 0, 93, 184, 1, 77, 132, 160, 75, 152, 88,
+        let expected_vsk = ViewingSecretKey::new(
+            [
+                81, 154, 68, 152, 72, 163, 82, 17, 125, 156, 193, 135, 129, 93, 227, 55, 224, 104,
+                119, 232, 13, 101, 241, 20, 175, 72, 192, 186, 176, 246, 140, 211,
+            ],
+            [
+                31, 40, 109, 41, 185, 61, 173, 79, 102, 171, 158, 245, 232, 71, 57, 157, 142, 117,
+                184, 235, 216, 71, 55, 44, 33, 156, 167, 133, 184, 92, 47, 174,
+            ],
+        );
+
+        let expected_vpk: [u8; 1184] = [
+            67, 150, 145, 133, 41, 124, 194, 102, 104, 131, 195, 8, 168, 170, 200, 40, 210, 84, 85,
+            117, 50, 99, 52, 23, 144, 23, 22, 140, 187, 76, 49, 224, 189, 64, 249, 72, 219, 35, 49,
+            162, 146, 121, 27, 179, 183, 215, 84, 177, 62, 37, 103, 97, 209, 201, 8, 162, 38, 109,
+            87, 44, 103, 136, 112, 236, 120, 60, 235, 130, 60, 212, 209, 77, 77, 220, 28, 156, 34,
+            7, 31, 35, 179, 102, 21, 54, 77, 99, 157, 210, 247, 151, 214, 182, 30, 57, 219, 40, 42,
+            188, 32, 30, 134, 126, 7, 22, 51, 241, 152, 8, 96, 5, 87, 168, 64, 62, 81, 247, 33,
+            228, 44, 180, 203, 60, 49, 66, 247, 143, 113, 106, 189, 44, 11, 182, 213, 247, 9, 22,
+            3, 208, 125, 2, 8, 103, 195, 202, 21, 33, 72, 139, 233, 19, 171, 172, 69, 253, 212, 37,
+            197, 66, 165, 207, 168, 69, 18, 24, 1, 100, 200, 175, 163, 247, 115, 17, 124, 84, 183,
+            92, 96, 142, 204, 149, 2, 90, 53, 110, 246, 188, 135, 240, 160, 231, 145, 23, 90, 209,
+            93, 166, 17, 119, 240, 49, 67, 234, 41, 187, 71, 23, 152, 159, 54, 206, 207, 26, 11,
+            32, 134, 202, 185, 201, 25, 59, 199, 182, 18, 236, 175, 254, 227, 195, 98, 52, 139,
+            162, 172, 195, 102, 178, 115, 59, 113, 108, 96, 89, 175, 145, 71, 202, 231, 153, 69, 3,
+            25, 60, 43, 215, 35, 70, 119, 16, 235, 98, 184, 252, 50, 36, 161, 244, 57, 13, 214,
+            115, 106, 225, 166, 7, 59, 44, 130, 197, 85, 69, 220, 81, 10, 1, 130, 227, 225, 47, 78,
+            251, 49, 232, 55, 2, 66, 64, 180, 220, 65, 140, 231, 188, 172, 153, 153, 152, 15, 186,
+            74, 6, 39, 16, 251, 216, 165, 145, 134, 3, 88, 131, 80, 114, 156, 119, 72, 130, 54,
+            159, 202, 23, 7, 130, 127, 156, 252, 113, 108, 85, 22, 120, 104, 12, 151, 187, 102, 64,
+            96, 137, 184, 68, 201, 20, 196, 196, 226, 220, 139, 174, 76, 109, 1, 179, 81, 156, 26,
+            136, 238, 106, 41, 197, 18, 16, 179, 91, 9, 8, 213, 123, 108, 58, 3, 102, 12, 87, 92,
+            217, 207, 166, 131, 17, 218, 134, 170, 27, 129, 145, 0, 65, 85, 99, 163, 97, 78, 228,
+            15, 54, 85, 201, 58, 204, 160, 250, 66, 41, 36, 165, 78, 50, 137, 78, 197, 103, 57, 79,
+            26, 14, 167, 104, 165, 129, 128, 90, 104, 148, 121, 135, 24, 126, 139, 235, 84, 183,
+            165, 115, 111, 83, 48, 184, 55, 84, 250, 115, 171, 195, 91, 114, 213, 104, 51, 110, 86,
+            148, 37, 139, 83, 49, 165, 171, 144, 90, 19, 91, 195, 111, 82, 185, 133, 211, 24, 186,
+            48, 230, 172, 190, 6, 65, 230, 26, 139, 8, 9, 34, 54, 28, 103, 84, 116, 38, 252, 105,
+            86, 123, 40, 31, 39, 64, 14, 253, 215, 147, 182, 218, 111, 148, 2, 18, 3, 197, 4, 129,
+            107, 136, 89, 122, 56, 47, 9, 179, 66, 227, 24, 193, 32, 4, 172, 210, 29, 152, 114,
+            134, 65, 249, 201, 178, 16, 206, 209, 39, 193, 109, 91, 122, 194, 26, 206, 37, 227, 55,
+            160, 214, 85, 196, 64, 97, 96, 66, 80, 34, 177, 83, 200, 44, 137, 175, 149, 114, 42,
+            229, 168, 248, 96, 106, 110, 182, 155, 62, 27, 179, 229, 139, 9, 213, 181, 116, 59,
+            118, 142, 91, 23, 165, 80, 43, 118, 18, 41, 143, 125, 59, 102, 61, 224, 120, 186, 10,
+            63, 119, 241, 168, 196, 87, 117, 138, 3, 151, 1, 129, 76, 154, 87, 200, 114, 124, 90,
+            212, 182, 54, 94, 20, 165, 243, 88, 77, 76, 152, 69, 19, 164, 106, 196, 204, 46, 239,
+            116, 42, 179, 65, 79, 39, 145, 63, 169, 199, 142, 6, 103, 118, 130, 49, 184, 208, 203,
+            36, 162, 216, 9, 188, 17, 86, 45, 35, 20, 178, 218, 121, 164, 243, 145, 57, 208, 130,
+            26, 27, 28, 100, 161, 148, 195, 54, 66, 114, 108, 146, 135, 66, 69, 232, 33, 197, 213,
+            131, 107, 31, 19, 162, 155, 164, 161, 103, 8, 192, 127, 188, 196, 252, 2, 155, 18, 130,
+            105, 53, 235, 200, 87, 203, 162, 95, 50, 158, 96, 210, 1, 45, 8, 26, 3, 192, 201, 182,
+            148, 192, 157, 106, 5, 161, 248, 66, 89, 56, 141, 126, 243, 143, 68, 90, 133, 193, 181,
+            198, 3, 169, 72, 66, 215, 195, 38, 37, 196, 103, 229, 89, 162, 210, 118, 12, 233, 162,
+            95, 164, 107, 97, 11, 120, 255, 164, 60, 117, 37, 108, 144, 185, 167, 40, 124, 69, 23,
+            37, 148, 222, 233, 43, 50, 16, 58, 53, 252, 8, 102, 88, 109, 28, 18, 22, 5, 49, 66,
+            149, 114, 203, 95, 216, 175, 10, 87, 206, 46, 9, 101, 212, 226, 84, 4, 231, 161, 106,
+            185, 31, 6, 101, 27, 54, 49, 85, 54, 84, 12, 250, 4, 49, 184, 134, 186, 23, 146, 54,
+            90, 186, 134, 129, 68, 10, 241, 201, 65, 251, 69, 110, 127, 220, 148, 38, 250, 148, 83,
+            32, 100, 131, 83, 133, 195, 54, 132, 63, 229, 85, 34, 172, 126, 68, 99, 197, 18, 197,
+            91, 221, 234, 66, 203, 156, 73, 46, 0, 54, 205, 11, 52, 172, 114, 193, 127, 171, 134,
+            109, 92, 37, 124, 181, 167, 191, 209, 148, 232, 26, 136, 230, 133, 181, 248, 117, 11,
+            45, 156, 136, 117, 144, 126, 239, 230, 144, 90, 57, 109, 158, 167, 19, 131, 215, 136,
+            85, 136, 10, 49, 9, 146, 64, 81, 28, 171, 53, 78, 40, 225, 94, 238, 70, 174, 125, 186,
+            155, 177, 202, 157, 63, 39, 152, 44, 105, 184, 140, 179, 204, 32, 210, 109, 35, 150,
+            194, 14, 98, 148, 176, 73, 185, 49, 135, 135, 244, 151, 147, 17, 103, 35, 242, 130, 3,
+            158, 198, 152, 83, 240, 198, 254, 145, 181, 67, 163, 14, 237, 249, 179, 252, 220, 67,
+            239, 7, 118, 131, 229, 137, 172, 151, 57, 121, 138, 204, 6, 208, 52, 168, 236, 123,
+            104, 68, 36, 141, 25, 168, 56, 199, 40, 200, 52, 97, 59, 55, 184, 196, 234, 204, 108,
+            75, 65, 177, 82, 207, 127, 128, 157, 0, 68, 163, 127, 152, 85, 123, 209, 163, 21, 119,
+            62, 250, 236, 58, 229, 220, 99, 209, 147, 10, 177, 115, 172, 96, 192, 80, 240, 66, 191,
+            138, 91, 52, 200, 132, 126, 255, 69, 98, 12, 140, 8, 158, 2, 153, 66, 211, 74, 242,
+            147, 148, 209, 6, 161, 76, 149, 158, 209, 163, 20, 76, 75, 192, 193, 162, 71, 134, 72,
+            160, 192, 10, 203, 4, 213, 23, 140, 196, 39, 231, 39, 16, 209, 228, 112, 244, 29, 27,
+            181, 190, 19, 134, 116, 173, 135, 190, 118, 4, 214, 194, 189, 224, 164, 91, 211, 182,
+            162, 226,
         ];
 
+        assert!(expected_ssk == child_node.value.0.secret_spending_key);
         assert!(expected_ccc == child_node.ccc);
         assert!(expected_nsk == child_node.value.0.private_key_holder.nullifier_secret_key);
         assert!(expected_npk == child_node.value.0.nullifier_public_key);
         assert!(expected_vsk == child_node.value.0.private_key_holder.viewing_secret_key);
-        assert!(expected_vpk_as_bytes == child_node.value.0.viewing_public_key.to_bytes());
+        assert!(expected_vpk == child_node.value.0.viewing_public_key.to_bytes());
     }
 }
diff --git a/key_protocol/src/key_management/mod.rs b/key_protocol/src/key_management/mod.rs
index ad98d7e2..c3bfc829 100644
--- a/key_protocol/src/key_management/mod.rs
+++ b/key_protocol/src/key_management/mod.rs
@@ -69,21 +69,15 @@ impl KeyChain {
     pub fn calculate_shared_secret_receiver(
         &self,
         ephemeral_public_key_sender: &EphemeralPublicKey,
-        index: Option<u32>,
-    ) -> SharedSecretKey {
-        SharedSecretKey::new(
-            self.secret_spending_key.generate_viewing_secret_key(index),
-            ephemeral_public_key_sender,
-        )
+    ) -> Option<SharedSecretKey> {
+        let vsk = &self.private_key_holder.viewing_secret_key;
+        SharedSecretKey::decapsulate(ephemeral_public_key_sender, &vsk.d, &vsk.z)
     }
 }
 
 #[cfg(test)]
 mod tests {
-    use aes_gcm::aead::OsRng;
     use base58::ToBase58 as _;
-    use k256::{AffinePoint, elliptic_curve::group::GroupEncoding as _};
-    use rand::RngCore as _;
 
     use super::*;
     use crate::key_management::{
@@ -106,14 +100,31 @@ mod tests {
     fn calculate_shared_secret_receiver() {
         let account_id_key_holder = KeyChain::new_os_random();
 
-        // Generate a random ephemeral public key sender
-        let mut scalar = [0; 32];
-        OsRng.fill_bytes(&mut scalar);
-        let ephemeral_public_key_sender = EphemeralPublicKey::from_scalar(scalar);
+        // Create a proper KEM ciphertext by encapsulating toward this key chain's VPK.
+        let (_, epk) = SharedSecretKey::encapsulate(&account_id_key_holder.viewing_public_key);
 
-        // Calculate shared secret
-        let _shared_secret = account_id_key_holder
-            .calculate_shared_secret_receiver(&ephemeral_public_key_sender, None);
+        let _shared_secret = account_id_key_holder.calculate_shared_secret_receiver(&epk);
+    }
+
+    #[test]
+    fn calculate_shared_secret_receiver_returns_none_for_malformed_epk() {
+        let key_chain = KeyChain::new_os_random();
+
+        let short_epk = EphemeralPublicKey(vec![42_u8; 100]);
+        assert!(
+            key_chain
+                .calculate_shared_secret_receiver(&short_epk)
+                .is_none(),
+            "short EphemeralPublicKey must return None"
+        );
+
+        let long_epk = EphemeralPublicKey(vec![42_u8; 1089]);
+        assert!(
+            key_chain
+                .calculate_shared_secret_receiver(&long_epk)
+                .is_none(),
+            "long EphemeralPublicKey must return None"
+        );
     }
 
     #[test]
@@ -135,12 +146,6 @@ mod tests {
         println!("======Prerequisites======");
         println!();
 
-        println!(
-            "Group generator {:?}",
-            hex::encode(AffinePoint::GENERATOR.to_bytes())
-        );
-        println!();
-
         println!("======Holders======");
         println!();
 
@@ -188,14 +193,12 @@ mod tests {
     fn non_trivial_chain_index() {
         let keys = account_with_chain_index_2_for_tests();
 
-        let eph_key_holder = EphemeralKeyHolder::new(&keys.nullifier_public_key);
+        let eph_key_holder = EphemeralKeyHolder::new(&keys.viewing_public_key);
 
-        let key_sender = eph_key_holder.calculate_shared_secret_sender(&keys.viewing_public_key);
-        let key_receiver = keys.calculate_shared_secret_receiver(
-            &eph_key_holder.generate_ephemeral_public_key(),
-            Some(2),
-        );
+        let key_sender = eph_key_holder.calculate_shared_secret_sender();
+        let key_receiver =
+            keys.calculate_shared_secret_receiver(eph_key_holder.ephemeral_public_key());
 
-        assert_eq!(key_sender.0, key_receiver.0);
+        assert_eq!(key_sender.0, key_receiver.unwrap().0);
     }
 }
diff --git a/key_protocol/src/key_management/secret_holders.rs b/key_protocol/src/key_management/secret_holders.rs
index f5e71ca8..553c939f 100644
--- a/key_protocol/src/key_management/secret_holders.rs
+++ b/key_protocol/src/key_management/secret_holders.rs
@@ -1,9 +1,7 @@
 use bip39::Mnemonic;
 use common::HashType;
-use nssa_core::{
-    NullifierPublicKey, NullifierSecretKey,
-    encryption::{Scalar, ViewingPublicKey},
-};
+use ml_kem;
+use nssa_core::{NullifierPublicKey, NullifierSecretKey, encryption::MlKem768EncapsulationKey};
 use rand::{RngCore as _, rngs::OsRng};
 use serde::{Deserialize, Serialize};
 use sha2::{Digest as _, digest::FixedOutput as _};
@@ -19,8 +17,20 @@ pub struct SeedHolder {
 /// Secret spending key object. Can produce `PrivateKeyHolder` objects.
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub struct SecretSpendingKey(pub [u8; 32]);
+/// Viewing secret key: the FIPS 203 KEM seed split into its two 32-byte halves `d` and `z`,
+/// from which the ML-KEM-768 decapsulation key is derived deterministically.
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
+pub struct ViewingSecretKey {
+    pub d: [u8; 32],
+    pub z: [u8; 32],
+}
 
-pub type ViewingSecretKey = Scalar;
+impl ViewingSecretKey {
+    #[must_use]
+    pub const fn new(d: [u8; 32], z: [u8; 32]) -> Self {
+        Self { d, z }
+    }
+}
 
 /// Private key holder. Produces public keys. Can produce `account_id`. Can produce shared secret
 /// for recepient.
@@ -114,7 +124,7 @@ impl SecretSpendingKey {
 
     #[must_use]
     #[expect(clippy::big_endian_bytes, reason = "BIP-032 uses big endian")]
-    pub fn generate_viewing_secret_key(&self, index: Option<u32>) -> ViewingSecretKey {
+    pub fn generate_viewing_secret_seed_key(&self, index: Option<u32>) -> ViewingSecretKey {
         const PREFIX: &[u8; 8] = b"LEE/keys";
         const SUFFIX_1: &[u8; 1] = &[2];
         const SUFFIX_2: &[u8; 19] = &[0; 19];
@@ -124,25 +134,57 @@ impl SecretSpendingKey {
             _ => index.expect("Expect a valid u32"),
         };
 
-        let mut hasher = sha2::Sha256::new();
-        hasher.update(PREFIX);
-        hasher.update(self.0);
-        hasher.update(SUFFIX_1);
-        hasher.update(index.to_be_bytes());
-        hasher.update(SUFFIX_2);
+        let mut bytes: Vec<u8> = Vec::with_capacity(64);
+        bytes.extend_from_slice(PREFIX);
+        bytes.extend_from_slice(&self.0);
+        bytes.extend_from_slice(SUFFIX_1);
+        bytes.extend_from_slice(&index.to_be_bytes());
+        bytes.extend_from_slice(SUFFIX_2);
+        let bytes: [u8; 64] = bytes
+            .try_into()
+            .expect("`generate_viewing_secret_seed_key`: bytes must be exactly 64");
 
-        hasher.finalize_fixed().into()
+        let full_seed = hmac_sha512::HMAC::mac(bytes, b"LEE_viewing_seed");
+
+        ViewingSecretKey::new(
+            *full_seed
+                .first_chunk::<32>()
+                .expect("hash_value is 64 bytes, must be safe to get first 32"),
+            *full_seed
+                .last_chunk::<32>()
+                .expect("hash_value is 64 bytes, must be safe to get last 32"),
+        )
+    }
+
+    #[must_use]
+    pub const fn generate_viewing_secret_key(seed: [u8; 64]) -> ViewingSecretKey {
+        ViewingSecretKey::new(
+            *seed.first_chunk::<32>().expect("seed is 64 bytes"),
+            *seed.last_chunk::<32>().expect("seed is 64 bytes"),
+        )
     }
 
     #[must_use]
     pub fn produce_private_key_holder(&self, index: Option<u32>) -> PrivateKeyHolder {
         PrivateKeyHolder {
             nullifier_secret_key: self.generate_nullifier_secret_key(index),
-            viewing_secret_key: self.generate_viewing_secret_key(index),
+            viewing_secret_key: self.generate_viewing_secret_seed_key(index),
         }
     }
 }
 
+impl From<&ViewingSecretKey> for MlKem768EncapsulationKey {
+    fn from(sk: &ViewingSecretKey) -> Self {
+        use ml_kem::{Kem, KeyExport as _, MlKem768, Seed};
+        let mut seed_bytes = [0_u8; 64];
+        seed_bytes[..32].copy_from_slice(&sk.d);
+        seed_bytes[32..].copy_from_slice(&sk.z);
+        let dk = <MlKem768 as Kem>::DecapsulationKey::from_seed(Seed::from(seed_bytes));
+        Self::from_bytes(dk.encapsulation_key().to_bytes().to_vec())
+            .expect("key_protocol::secret_holders::From<&ViewingSecretKey>: ML-KEM-768 encapsulation key is always 1184 bytes")
+    }
+}
+
 impl PrivateKeyHolder {
     #[must_use]
     pub fn generate_nullifier_public_key(&self) -> NullifierPublicKey {
@@ -150,8 +192,8 @@ impl PrivateKeyHolder {
     }
 
     #[must_use]
-    pub fn generate_viewing_public_key(&self) -> ViewingPublicKey {
-        ViewingPublicKey::from_scalar(self.viewing_secret_key)
+    pub fn generate_viewing_public_key(&self) -> MlKem768EncapsulationKey {
+        MlKem768EncapsulationKey::from(&self.viewing_secret_key)
     }
 }
 
@@ -183,8 +225,7 @@ mod tests {
         assert_eq!(seed_holder.seed.len(), 64);
 
         let top_secret_key_holder = seed_holder.produce_top_secret_key_holder();
-
-        let _vsk = top_secret_key_holder.generate_viewing_secret_key(None);
+        let _vsk = top_secret_key_holder.generate_viewing_secret_seed_key(None);
     }
 
     #[test]
diff --git a/nssa/Cargo.toml b/nssa/Cargo.toml
index ee9b8bb6..ce9a3aeb 100644
--- a/nssa/Cargo.toml
+++ b/nssa/Cargo.toml
@@ -31,6 +31,7 @@ risc0-build = "3.0.3"
 risc0-binfmt = "3.0.2"
 
 [dev-dependencies]
+nssa_core = { workspace = true, features = ["test_utils"] }
 token_core.workspace = true
 authenticated_transfer_core.workspace = true
 test_program_methods.workspace = true
diff --git a/nssa/core/Cargo.toml b/nssa/core/Cargo.toml
index d9e80af4..0ed8f4b4 100644
--- a/nssa/core/Cargo.toml
+++ b/nssa/core/Cargo.toml
@@ -16,7 +16,7 @@ thiserror.workspace = true
 bytemuck.workspace = true
 bytesize.workspace = true
 base58.workspace = true
-k256 = { workspace = true, optional = true }
+ml-kem = { workspace = true, optional = true, features = ["getrandom"] }
 chacha20 = { version = "0.10" }
 
 [dev-dependencies]
@@ -24,4 +24,5 @@ serde_json.workspace = true
 
 [features]
 default = []
-host = ["dep:k256"]
+host = ["dep:ml-kem"]
+test_utils = ["host"]
diff --git a/nssa/core/src/encoding.rs b/nssa/core/src/encoding.rs
index ac9317c2..4e6481ef 100644
--- a/nssa/core/src/encoding.rs
+++ b/nssa/core/src/encoding.rs
@@ -7,7 +7,7 @@ use std::io::Read as _;
 #[cfg(feature = "host")]
 use crate::Nullifier;
 #[cfg(feature = "host")]
-use crate::encryption::shared_key_derivation::Secp256k1Point;
+use crate::encryption::EphemeralPublicKey;
 #[cfg(feature = "host")]
 use crate::error::NssaCoreError;
 use crate::{
@@ -158,16 +158,17 @@ impl Ciphertext {
 }
 
 #[cfg(feature = "host")]
-impl Secp256k1Point {
-    /// Converts the point to bytes.
+impl EphemeralPublicKey {
+    /// Serializes the ML-KEM-768 ciphertext to bytes (always 1088 bytes).
     #[must_use]
-    pub fn to_bytes(&self) -> [u8; 33] {
-        self.0.clone().try_into().unwrap()
+    pub fn to_bytes(&self) -> Vec<u8> {
+        self.0.clone()
     }
 
-    /// Deserializes a secp256k1 point from a cursor.
+    /// Deserializes an ML-KEM-768 ciphertext from a cursor.
+    /// Reads exactly 1088 bytes — the fixed ciphertext size for ML-KEM-768.
     pub fn from_cursor(cursor: &mut Cursor<&[u8]>) -> Result<Self, NssaCoreError> {
-        let mut value = vec![0; 33];
+        let mut value = vec![0_u8; 1088];
         cursor.read_exact(&mut value)?;
         Ok(Self(value))
     }
diff --git a/nssa/core/src/encryption/mod.rs b/nssa/core/src/encryption/mod.rs
index 4b675d0e..7f1eadc4 100644
--- a/nssa/core/src/encryption/mod.rs
+++ b/nssa/core/src/encryption/mod.rs
@@ -6,7 +6,7 @@ use chacha20::{
 use risc0_zkvm::sha::{Impl, Sha256 as _};
 use serde::{Deserialize, Serialize};
 #[cfg(feature = "host")]
-pub use shared_key_derivation::{EphemeralPublicKey, EphemeralSecretKey, ViewingPublicKey};
+pub use shared_key_derivation::{EphemeralPublicKey, MlKem768EncapsulationKey, ViewingPublicKey};
 
 use crate::{Commitment, account::Account, program::PrivateAccountKind};
 #[cfg(feature = "host")]
@@ -154,4 +154,41 @@ mod tests {
 
         assert_eq!(account_ct.0.len(), pda_ct.0.len());
     }
+
+    /// Verifies the full account-note pipeline: ML-KEM-768 encapsulation/decapsulation
+    /// feeds the correct shared secret into the SHA-256 KDF and `ChaCha20` round-trip.
+    #[cfg(feature = "host")]
+    #[test]
+    fn kem_to_chacha20_round_trip() {
+        let d = [1_u8; 32];
+        let z = [2_u8; 32];
+        let vpk = shared_key_derivation::ViewingPublicKey::from_seed(&d, &z);
+
+        let (sender_ss, epk) = SharedSecretKey::encapsulate(&vpk);
+        let receiver_ss = SharedSecretKey::decapsulate(&epk, &d, &z).unwrap();
+
+        let account = Account {
+            program_owner: [12_u32; 8],
+            balance: 999,
+            ..Account::default()
+        };
+        let kind = PrivateAccountKind::Regular(0);
+        let commitment = crate::Commitment::new(&AccountId::new([7_u8; 32]), &account);
+
+        let ct = EncryptionScheme::encrypt(&account, &kind, &sender_ss, &commitment, 0);
+        let (decoded_kind, decoded_account) =
+            EncryptionScheme::decrypt(&ct, &receiver_ss, &commitment, 0)
+                .expect("decryption must succeed with correct shared secret");
+
+        assert_eq!(decoded_account, account);
+        assert_eq!(decoded_kind, kind);
+
+        // Wrong shared secret must not decrypt correctly.
+        let wrong_ss = SharedSecretKey([0_u8; 32]);
+        let bad = EncryptionScheme::decrypt(&ct, &wrong_ss, &commitment, 0);
+        assert!(
+            bad.is_none() || bad.is_some_and(|(_, a)| a.balance != 999),
+            "wrong shared secret must not produce the correct plaintext"
+        );
+    }
 }
diff --git a/nssa/core/src/encryption/shared_key_derivation.rs b/nssa/core/src/encryption/shared_key_derivation.rs
index 8ea5aac8..0e8f0f94 100644
--- a/nssa/core/src/encryption/shared_key_derivation.rs
+++ b/nssa/core/src/encryption/shared_key_derivation.rs
@@ -1,78 +1,232 @@
-#![expect(
-    clippy::arithmetic_side_effects,
-    reason = "Multiplication of finite field elements can't overflow"
-)]
-
-use std::fmt::Write as _;
-
 use borsh::{BorshDeserialize, BorshSerialize};
-use k256::{
-    AffinePoint, EncodedPoint, FieldBytes, ProjectivePoint,
-    elliptic_curve::{
-        PrimeField as _,
-        sec1::{FromEncodedPoint as _, ToEncodedPoint as _},
-    },
-};
+use ml_kem::{Decapsulate as _, Encapsulate as _, KeyExport as _, Seed};
 use serde::{Deserialize, Serialize};
 
-use crate::{SharedSecretKey, encryption::Scalar};
+use crate::SharedSecretKey;
 
+/// The ML-KEM-768 ciphertext produced during encapsulation; transmitted on-wire in place of the
+/// former ECDH ephemeral public key.  Always 1088 bytes for ML-KEM-768.
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Eq, BorshSerialize, BorshDeserialize)]
+pub struct EphemeralPublicKey(pub Vec<u8>);
+
+/// ML-KEM-768 encapsulation key bytes (1184 bytes, opaque to this crate).
 #[derive(
-    Serialize, Deserialize, Clone, PartialEq, Eq, PartialOrd, Ord, BorshSerialize, BorshDeserialize,
+    Serialize,
+    Deserialize,
+    Clone,
+    Debug,
+    PartialEq,
+    Eq,
+    PartialOrd,
+    Ord,
+    BorshSerialize,
+    BorshDeserialize,
 )]
-pub struct Secp256k1Point(pub Vec<u8>);
+pub struct MlKem768EncapsulationKey(Vec<u8>);
 
-impl std::fmt::Debug for Secp256k1Point {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let hex: String = self.0.iter().fold(String::new(), |mut acc, b| {
-            write!(acc, "{b:02x}").expect("writing to string should not fail");
-            acc
-        });
-        write!(f, "Secp256k1Point({hex})")
+pub type ViewingPublicKey = MlKem768EncapsulationKey;
+
+impl MlKem768EncapsulationKey {
+    /// Expected byte length of an ML-KEM-768 encapsulation key.
+    pub const LEN: usize = 1184;
+
+    /// Construct from raw bytes, returning an error if the length is not [`Self::LEN`].
+    pub fn from_bytes(bytes: Vec<u8>) -> Result<Self, crate::error::NssaCoreError> {
+        if bytes.len() != Self::LEN {
+            return Err(crate::error::NssaCoreError::DeserializationError(format!(
+                "MlKem768EncapsulationKey must be {} bytes, got {}",
+                Self::LEN,
+                bytes.len()
+            )));
+        }
+        Ok(Self(bytes))
     }
-}
 
-impl Secp256k1Point {
     #[must_use]
-    pub fn from_scalar(value: Scalar) -> Self {
-        let x_bytes: FieldBytes = value.into();
-        let x = k256::Scalar::from_repr(x_bytes).unwrap();
-
-        let p = ProjectivePoint::GENERATOR * x;
-        let q = AffinePoint::from(p);
-        let enc = q.to_encoded_point(true);
-
-        Self(enc.as_bytes().to_vec())
+    pub fn to_bytes(&self) -> &[u8] {
+        &self.0
     }
-}
 
-pub type EphemeralSecretKey = Scalar;
-pub type EphemeralPublicKey = Secp256k1Point;
-pub type ViewingPublicKey = Secp256k1Point;
-impl From<&EphemeralSecretKey> for EphemeralPublicKey {
-    fn from(value: &EphemeralSecretKey) -> Self {
-        Self::from_scalar(*value)
+    /// Derive the ML-KEM-768 encapsulation key from the FIPS 203 seed halves `d` and `z`.
+    #[must_use]
+    pub fn from_seed(d: &[u8; 32], z: &[u8; 32]) -> Self {
+        let mut seed = Seed::default();
+        seed[..32].copy_from_slice(d);
+        seed[32..].copy_from_slice(z);
+        let dk = ml_kem::DecapsulationKey768::from_seed(seed);
+        Self(dk.encapsulation_key().to_bytes().to_vec())
     }
 }
 
 impl SharedSecretKey {
-    /// Creates a new shared secret key from a scalar and a point.
+    /// Sender: encapsulate a fresh shared secret toward `ek`.
+    ///
+    /// Returns `(shared_secret, ciphertext)`.  The ciphertext must be included in the transaction
+    /// as the `EphemeralPublicKey`; the receiver recovers the same shared secret via
+    /// [`Self::decapsulate`].
     #[must_use]
-    pub fn new(scalar: Scalar, point: &Secp256k1Point) -> Self {
-        let scalar = k256::Scalar::from_repr(scalar.into()).unwrap();
-        let point: [u8; 33] = point.0.clone().try_into().unwrap();
+    pub fn encapsulate(ek: &MlKem768EncapsulationKey) -> (Self, EphemeralPublicKey) {
+        let ek_bytes: ml_kem::kem::Key<ml_kem::EncapsulationKey768> =
+            ek.0.as_slice()
+                .try_into()
+                .expect("MlKem768EncapsulationKey must be 1184 bytes");
+        let ek_obj = ml_kem::EncapsulationKey768::new(&ek_bytes).expect(
+            "MlKem768EncapsulationKey bytes must encode a valid ML-KEM-768 encapsulation key",
+        );
+        let (ct, ss) = ek_obj.encapsulate();
+        let ss_bytes: [u8; 32] = ss
+            .as_slice()
+            .try_into()
+            .expect("ML-KEM shared key is 32 bytes");
+        (Self(ss_bytes), EphemeralPublicKey(ct.to_vec()))
+    }
 
-        let encoded = EncodedPoint::from_bytes(point).unwrap();
-        let pubkey_affine = AffinePoint::from_encoded_point(&encoded).unwrap();
+    /// Deterministically encapsulate a shared secret toward `ek` for use in tests.
+    ///
+    /// The shared secret has no secret entropy — it is fully determined by `ek`,
+    /// `message_hash`, and `output_index`, all of which are public. This makes it
+    /// unsuitable for real encryption but useful for producing stable, reproducible
+    /// shared secrets in unit tests. Use a distinct `output_index` per output to
+    /// avoid EPK collisions across multiple outputs in the same test.
+    ///
+    /// For production use [`Self::encapsulate`], which draws randomness from the OS.
+    #[cfg(any(test, feature = "test_utils"))]
+    #[must_use]
+    pub fn encapsulate_deterministic(
+        ek: &MlKem768EncapsulationKey,
+        message_hash: &[u8; 32],
+        output_index: u32,
+    ) -> (Self, EphemeralPublicKey) {
+        use risc0_zkvm::sha::{Impl, Sha256 as _};
 
-        let shared = ProjectivePoint::from(pubkey_affine) * scalar;
-        let shared_affine = shared.to_affine();
+        let mut input = Vec::with_capacity(36);
+        input.extend_from_slice(message_hash);
+        input.extend_from_slice(&output_index.to_le_bytes());
+        let hash = Impl::hash_bytes(&input);
+        let m: ml_kem::B32 =
+            ml_kem::array::Array::try_from(hash.as_bytes()).expect("SHA-256 output is 32 bytes");
 
-        let shared_affine_encoded = shared_affine.to_encoded_point(false);
-        let x_bytes_slice = shared_affine_encoded.x().unwrap();
-        let mut x_bytes = [0_u8; 32];
-        x_bytes.copy_from_slice(x_bytes_slice);
+        let ek_bytes: ml_kem::kem::Key<ml_kem::EncapsulationKey768> =
+            ek.0.as_slice()
+                .try_into()
+                .expect("MlKem768EncapsulationKey must be 1184 bytes");
+        let ek_obj = ml_kem::EncapsulationKey768::new(&ek_bytes).expect(
+            "MlKem768EncapsulationKey bytes must encode a valid ML-KEM-768 encapsulation key",
+        );
+        let (ct, ss) = ek_obj.encapsulate_deterministic(&m);
+        let ss_bytes: [u8; 32] = ss
+            .as_slice()
+            .try_into()
+            .expect("ML-KEM shared key is 32 bytes");
+        (Self(ss_bytes), EphemeralPublicKey(ct.to_vec()))
+    }
 
-        Self(x_bytes)
+    /// Receiver: decapsulate the shared secret from a KEM ciphertext.
+    ///
+    /// Returns `None` if the `EphemeralPublicKey` is not exactly 1088 bytes — callers on
+    /// the wallet scan path should skip the output rather than panic on malformed chain data.
+    ///
+    /// `d` and `z` are the two 32-byte halves of the FIPS 203 `ViewingSecretKey` seed.
+    #[must_use]
+    pub fn decapsulate(
+        ciphertext: &EphemeralPublicKey,
+        d: &[u8; 32],
+        z: &[u8; 32],
+    ) -> Option<Self> {
+        let mut seed = Seed::default();
+        seed[..32].copy_from_slice(d);
+        seed[32..].copy_from_slice(z);
+        let dk = ml_kem::DecapsulationKey768::from_seed(seed);
+        let ss = dk.decapsulate_slice(&ciphertext.0).ok()?;
+        let ss_bytes: [u8; 32] = ss
+            .as_slice()
+            .try_into()
+            .expect("ML-KEM shared key is 32 bytes");
+        Some(Self(ss_bytes))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use ml_kem::KeyExport as _;
+
+    use super::*;
+
+    #[test]
+    fn encapsulate_decapsulate_round_trip() {
+        let d = [1_u8; 32];
+        let z = [2_u8; 32];
+
+        let mut seed = Seed::default();
+        seed[..32].copy_from_slice(&d);
+        seed[32..].copy_from_slice(&z);
+
+        let dk = ml_kem::DecapsulationKey768::from_seed(seed);
+        let ek_bytes = dk.encapsulation_key().to_bytes();
+        let ek = MlKem768EncapsulationKey(ek_bytes.to_vec());
+
+        let (sender_ss, epk) = SharedSecretKey::encapsulate(&ek);
+        let receiver_ss = SharedSecretKey::decapsulate(&epk, &d, &z).unwrap();
+
+        assert_eq!(sender_ss.0, receiver_ss.0, "shared secrets must match");
+        assert_eq!(epk.0.len(), 1088, "ML-KEM-768 ciphertext is 1088 bytes");
+        assert_eq!(
+            ek.0.len(),
+            1184,
+            "ML-KEM-768 encapsulation key is 1184 bytes"
+        );
+    }
+
+    #[test]
+    fn decapsulate_returns_none_for_malformed_epk() {
+        let d = [1_u8; 32];
+        let z = [2_u8; 32];
+
+        // Too short — 100 bytes instead of 1088.
+        let short_epk = EphemeralPublicKey(vec![42_u8; 100]);
+        assert!(
+            SharedSecretKey::decapsulate(&short_epk, &d, &z).is_none(),
+            "short EphemeralPublicKey must return None"
+        );
+
+        // Too long — 1089 bytes instead of 1088.
+        let long_epk = EphemeralPublicKey(vec![42_u8; 1089]);
+        assert!(
+            SharedSecretKey::decapsulate(&long_epk, &d, &z).is_none(),
+            "long EphemeralPublicKey must return None"
+        );
+
+        // Empty.
+        let empty_epk = EphemeralPublicKey(vec![]);
+        assert!(
+            SharedSecretKey::decapsulate(&empty_epk, &d, &z).is_none(),
+            "empty EphemeralPublicKey must return None"
+        );
+    }
+
+    #[test]
+    fn different_vpks_produce_different_shared_secrets() {
+        let (d1, z1) = ([1_u8; 32], [2_u8; 32]);
+        let (d2, z2) = ([3_u8; 32], [4_u8; 32]);
+
+        let ek1 = {
+            let mut seed = Seed::default();
+            seed[..32].copy_from_slice(&d1);
+            seed[32..].copy_from_slice(&z1);
+            let dk = ml_kem::DecapsulationKey768::from_seed(seed);
+            MlKem768EncapsulationKey(dk.encapsulation_key().to_bytes().to_vec())
+        };
+        let ek2 = {
+            let mut seed = Seed::default();
+            seed[..32].copy_from_slice(&d2);
+            seed[32..].copy_from_slice(&z2);
+            let dk = ml_kem::DecapsulationKey768::from_seed(seed);
+            MlKem768EncapsulationKey(dk.encapsulation_key().to_bytes().to_vec())
+        };
+
+        let (ss1, _) = SharedSecretKey::encapsulate(&ek1);
+        let (ss2, _) = SharedSecretKey::encapsulate(&ek2);
+
+        assert_ne!(ss1.0, ss2.0);
     }
 }
diff --git a/nssa/src/privacy_preserving_transaction/circuit.rs b/nssa/src/privacy_preserving_transaction/circuit.rs
index 902f5eaa..2c14e2a9 100644
--- a/nssa/src/privacy_preserving_transaction/circuit.rs
+++ b/nssa/src/privacy_preserving_transaction/circuit.rs
@@ -243,8 +243,8 @@ mod tests {
 
         let expected_sender_pre = sender.clone();
 
-        let esk = [3; 32];
-        let shared_secret = SharedSecretKey::new(esk, &recipient_keys.vpk());
+        let shared_secret =
+            SharedSecretKey::encapsulate_deterministic(&recipient_keys.vpk(), &[0_u8; 32], 0).0;
 
         let (output, proof) = execute_and_prove(
             vec![sender, recipient],
@@ -340,11 +340,11 @@ mod tests {
             Commitment::new(&recipient_account_id, &expected_private_account_2),
         ];
 
-        let esk_1 = [3; 32];
-        let shared_secret_1 = SharedSecretKey::new(esk_1, &sender_keys.vpk());
+        let shared_secret_1 =
+            SharedSecretKey::encapsulate_deterministic(&sender_keys.vpk(), &[0_u8; 32], 0).0;
 
-        let esk_2 = [5; 32];
-        let shared_secret_2 = SharedSecretKey::new(esk_2, &recipient_keys.vpk());
+        let shared_secret_2 =
+            SharedSecretKey::encapsulate_deterministic(&recipient_keys.vpk(), &[0_u8; 32], 1).0;
 
         let (output, proof) = execute_and_prove(
             vec![sender_pre, recipient],
@@ -418,8 +418,8 @@ mod tests {
         ))
         .unwrap();
 
-        let esk = [3; 32];
-        let shared_secret = SharedSecretKey::new(esk, &account_keys.vpk());
+        let shared_secret =
+            SharedSecretKey::encapsulate_deterministic(&account_keys.vpk(), &[0_u8; 32], 0).0;
 
         let program_with_deps = ProgramWithDependencies::new(
             validity_window_chain_caller,
@@ -449,7 +449,8 @@ mod tests {
         let npk = keys.npk();
         let seed = PdaSeed::new([42; 32]);
         let identifier: u128 = 99;
-        let shared_secret = SharedSecretKey::new([55; 32], &keys.vpk());
+        let shared_secret =
+            SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
 
         let account_id = AccountId::for_private_pda(&program.id(), &seed, &npk, identifier);
         let pre_state = AccountWithMetadata::new(Account::default(), false, account_id);
@@ -487,7 +488,8 @@ mod tests {
         let keys = test_private_account_keys_1();
         let npk = keys.npk();
         let seed = PdaSeed::new([42; 32]);
-        let shared_secret_pda = SharedSecretKey::new([55; 32], &keys.vpk());
+        let shared_secret_pda =
+            SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
 
         // PDA (new, private PDA)
         let pda_id = AccountId::for_private_pda(&program.id(), &seed, &npk, 0);
@@ -526,7 +528,8 @@ mod tests {
         let keys = test_private_account_keys_1();
         let npk = keys.npk();
         let seed = PdaSeed::new([42; 32]);
-        let shared_secret_pda = SharedSecretKey::new([55; 32], &keys.vpk());
+        let shared_secret_pda =
+            SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
 
         // PDA (new, private PDA)
         let pda_id = AccountId::for_private_pda(&program.id(), &seed, &npk, 0);
@@ -581,7 +584,8 @@ mod tests {
         let shared_keys = test_private_account_keys_1();
         let shared_npk = shared_keys.npk();
         let shared_identifier: u128 = 42;
-        let shared_secret = SharedSecretKey::new([55; 32], &shared_keys.vpk());
+        let shared_secret =
+            SharedSecretKey::encapsulate_deterministic(&shared_keys.vpk(), &[0_u8; 32], 0).0;
 
         // Sender: public account with balance, owned by auth-transfer
         let sender_id = AccountId::new([99; 32]);
@@ -632,7 +636,7 @@ mod tests {
         let program = Program::authenticated_transfer_program();
         let keys = test_private_account_keys_1();
         let identifier: u128 = 99;
-        let ssk = SharedSecretKey::new([55; 32], &keys.vpk());
+        let ssk = SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
         let account_id = AccountId::for_regular_private_account(&keys.npk(), identifier);
         let pre = AccountWithMetadata::new(Account::default(), true, account_id);
 
@@ -662,7 +666,7 @@ mod tests {
         let program = Program::authenticated_transfer_program();
         let keys = test_private_account_keys_1();
         let identifier: u128 = 99;
-        let ssk = SharedSecretKey::new([55; 32], &keys.vpk());
+        let ssk = SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
 
         let sender = AccountWithMetadata::new(
             Account {
@@ -707,7 +711,7 @@ mod tests {
         let program = Program::authenticated_transfer_program();
         let keys = test_private_account_keys_1();
         let identifier: u128 = 99;
-        let ssk = SharedSecretKey::new([55; 32], &keys.vpk());
+        let ssk = SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
         let account_id = AccountId::for_regular_private_account(&keys.npk(), identifier);
         let account = Account {
             program_owner: program.id(),
@@ -756,7 +760,7 @@ mod tests {
         let npk = keys.npk();
         let seed = PdaSeed::new([42; 32]);
         let identifier: u128 = 99;
-        let ssk = SharedSecretKey::new([55; 32], &keys.vpk());
+        let ssk = SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
 
         let auth_transfer_id = auth_transfer.id();
         let pda_id = AccountId::for_private_pda(&program.id(), &seed, &npk, identifier);
@@ -811,7 +815,8 @@ mod tests {
         let keys = test_private_account_keys_1();
         let npk = keys.npk();
         let seed = PdaSeed::new([42; 32]);
-        let shared_secret = SharedSecretKey::new([55; 32], &keys.vpk());
+        let shared_secret =
+            SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
 
         let account_id = AccountId::for_private_pda(&program.id(), &seed, &npk, 5);
         let pre_state = AccountWithMetadata::new(Account::default(), false, account_id);
@@ -838,7 +843,7 @@ mod tests {
         let keys = test_private_account_keys_1();
         let npk = keys.npk();
         let seed = PdaSeed::new([42; 32]);
-        let ssk = SharedSecretKey::new([55; 32], &keys.vpk());
+        let ssk = SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
 
         let auth_transfer_id = auth_transfer.id();
         let pda_id = AccountId::for_private_pda(&program.id(), &seed, &npk, 5);
diff --git a/nssa/src/privacy_preserving_transaction/message.rs b/nssa/src/privacy_preserving_transaction/message.rs
index 3a968bfb..2dc66485 100644
--- a/nssa/src/privacy_preserving_transaction/message.rs
+++ b/nssa/src/privacy_preserving_transaction/message.rs
@@ -143,7 +143,7 @@ pub mod tests {
         Commitment, EncryptionScheme, Nullifier, NullifierPublicKey, PrivateAccountKind,
         SharedSecretKey,
         account::{Account, AccountId, Nonce},
-        encryption::{EphemeralPublicKey, ViewingPublicKey},
+        encryption::ViewingPublicKey,
         program::{BlockValidityWindow, TimestampValidityWindow},
     };
     use sha2::{Digest as _, Sha256};
@@ -208,7 +208,7 @@ pub mod tests {
         let nonces_bytes: &[u8] = &[1, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
         // all remaining vec fields are empty: u32 len=0
         let empty_vec_bytes: &[u8] = &[0_u8; 4];
-        // validity windows: unbounded = {from: None (0u8), to: None (0u8)}
+        // validity windows: unbounded = {from: None (0_u8), to: None (0_u8)}
         let unbounded_window_bytes: &[u8] = &[0_u8; 2];
 
         let expected_borsh_vec: Vec<u8> = [
@@ -246,13 +246,11 @@ pub mod tests {
     #[test]
     fn encrypted_account_data_constructor() {
         let npk = NullifierPublicKey::from(&[1; 32]);
-        let vpk = ViewingPublicKey::from_scalar([2; 32]);
+        let vpk = ViewingPublicKey::from_seed(&[2_u8; 32], &[3_u8; 32]);
         let account = Account::default();
         let account_id = nssa_core::account::AccountId::for_regular_private_account(&npk, 0);
         let commitment = Commitment::new(&account_id, &account);
-        let esk = [3; 32];
-        let shared_secret = SharedSecretKey::new(esk, &vpk);
-        let epk = EphemeralPublicKey::from_scalar(esk);
+        let (shared_secret, epk) = SharedSecretKey::encapsulate_deterministic(&vpk, &[0_u8; 32], 0);
         let ciphertext = EncryptionScheme::encrypt(
             &account,
             &PrivateAccountKind::Regular(0),
diff --git a/nssa/src/state.rs b/nssa/src/state.rs
index 25297c99..b1ec22ee 100644
--- a/nssa/src/state.rs
+++ b/nssa/src/state.rs
@@ -423,7 +423,7 @@ pub mod tests {
         BlockId, Commitment, InputAccountIdentity, Nullifier, NullifierPublicKey,
         NullifierSecretKey, SharedSecretKey, Timestamp,
         account::{Account, AccountId, AccountWithMetadata, Nonce, data::Data},
-        encryption::{EphemeralPublicKey, Scalar, ViewingPublicKey},
+        encryption::{EphemeralPublicKey, ViewingPublicKey},
         program::{
             BlockValidityWindow, ExecutionValidationError, PdaSeed, ProgramId,
             TimestampValidityWindow, WrappedBalanceSum,
@@ -538,7 +538,8 @@ pub mod tests {
 
     pub struct TestPrivateKeys {
         pub nsk: NullifierSecretKey,
-        pub vsk: Scalar,
+        pub d: [u8; 32],
+        pub z: [u8; 32],
     }
 
     impl TestPrivateKeys {
@@ -547,7 +548,7 @@ pub mod tests {
         }
 
         pub fn vpk(&self) -> ViewingPublicKey {
-            ViewingPublicKey::from_scalar(self.vsk)
+            ViewingPublicKey::from_seed(&self.d, &self.z)
         }
     }
 
@@ -1335,14 +1336,16 @@ pub mod tests {
     pub fn test_private_account_keys_1() -> TestPrivateKeys {
         TestPrivateKeys {
             nsk: [13; 32],
-            vsk: [31; 32],
+            d: [31; 32],
+            z: [32; 32],
         }
     }
 
     pub fn test_private_account_keys_2() -> TestPrivateKeys {
         TestPrivateKeys {
             nsk: [38; 32],
-            vsk: [83; 32],
+            d: [83; 32],
+            z: [84; 32],
         }
     }
 
@@ -1363,9 +1366,8 @@ pub mod tests {
         let recipient =
             AccountWithMetadata::new(Account::default(), false, (&recipient_keys.npk(), 0));
 
-        let esk = [3; 32];
-        let shared_secret = SharedSecretKey::new(esk, &recipient_keys.vpk());
-        let epk = EphemeralPublicKey::from_scalar(esk);
+        let (shared_secret, epk) =
+            SharedSecretKey::encapsulate_deterministic(&recipient_keys.vpk(), &[0_u8; 32], 0);
 
         let (output, proof) = circuit::execute_and_prove(
             vec![sender, recipient],
@@ -1415,13 +1417,11 @@ pub mod tests {
         let recipient_pre =
             AccountWithMetadata::new(Account::default(), false, (&recipient_keys.npk(), 0));
 
-        let esk_1 = [3; 32];
-        let shared_secret_1 = SharedSecretKey::new(esk_1, &sender_keys.vpk());
-        let epk_1 = EphemeralPublicKey::from_scalar(esk_1);
+        let (shared_secret_1, epk_1) =
+            SharedSecretKey::encapsulate_deterministic(&sender_keys.vpk(), &[0_u8; 32], 0);
 
-        let esk_2 = [3; 32];
-        let shared_secret_2 = SharedSecretKey::new(esk_2, &recipient_keys.vpk());
-        let epk_2 = EphemeralPublicKey::from_scalar(esk_2);
+        let (shared_secret_2, epk_2) =
+            SharedSecretKey::encapsulate_deterministic(&recipient_keys.vpk(), &[0_u8; 32], 1);
 
         let (output, proof) = circuit::execute_and_prove(
             vec![sender_pre, recipient_pre],
@@ -1485,9 +1485,8 @@ pub mod tests {
             *recipient_account_id,
         );
 
-        let esk = [3; 32];
-        let shared_secret = SharedSecretKey::new(esk, &sender_keys.vpk());
-        let epk = EphemeralPublicKey::from_scalar(esk);
+        let (shared_secret, epk) =
+            SharedSecretKey::encapsulate_deterministic(&sender_keys.vpk(), &[0_u8; 32], 0);
 
         let (output, proof) = circuit::execute_and_prove(
             vec![sender_pre, recipient_pre],
@@ -1995,14 +1994,24 @@ pub mod tests {
             Program::serialize_instruction(10_u128).unwrap(),
             vec![
                 InputAccountIdentity::PrivateAuthorizedUpdate {
-                    ssk: SharedSecretKey::new([55; 32], &sender_keys.vpk()),
+                    ssk: SharedSecretKey::encapsulate_deterministic(
+                        &sender_keys.vpk(),
+                        &[0_u8; 32],
+                        0,
+                    )
+                    .0,
                     nsk: recipient_keys.nsk,
                     membership_proof: (0, vec![]),
                     identifier: 0,
                 },
                 InputAccountIdentity::PrivateUnauthorized {
                     npk: recipient_keys.npk(),
-                    ssk: SharedSecretKey::new([56; 32], &recipient_keys.vpk()),
+                    ssk: SharedSecretKey::encapsulate_deterministic(
+                        &recipient_keys.vpk(),
+                        &[0_u8; 32],
+                        0,
+                    )
+                    .0,
                     identifier: 0,
                 },
             ],
@@ -2041,14 +2050,24 @@ pub mod tests {
             Program::serialize_instruction(10_u128).unwrap(),
             vec![
                 InputAccountIdentity::PrivateAuthorizedUpdate {
-                    ssk: SharedSecretKey::new([55; 32], &sender_keys.vpk()),
+                    ssk: SharedSecretKey::encapsulate_deterministic(
+                        &sender_keys.vpk(),
+                        &[0_u8; 32],
+                        0,
+                    )
+                    .0,
                     nsk: sender_keys.nsk,
                     membership_proof: (0, vec![]),
                     identifier: 0,
                 },
                 InputAccountIdentity::PrivateUnauthorized {
                     npk: recipient_keys.npk(),
-                    ssk: SharedSecretKey::new([56; 32], &recipient_keys.vpk()),
+                    ssk: SharedSecretKey::encapsulate_deterministic(
+                        &recipient_keys.vpk(),
+                        &[0_u8; 32],
+                        0,
+                    )
+                    .0,
                     identifier: 0,
                 },
             ],
@@ -2087,14 +2106,24 @@ pub mod tests {
             Program::serialize_instruction(10_u128).unwrap(),
             vec![
                 InputAccountIdentity::PrivateAuthorizedUpdate {
-                    ssk: SharedSecretKey::new([55; 32], &sender_keys.vpk()),
+                    ssk: SharedSecretKey::encapsulate_deterministic(
+                        &sender_keys.vpk(),
+                        &[0_u8; 32],
+                        0,
+                    )
+                    .0,
                     nsk: sender_keys.nsk,
                     membership_proof: (0, vec![]),
                     identifier: 0,
                 },
                 InputAccountIdentity::PrivateUnauthorized {
                     npk: recipient_keys.npk(),
-                    ssk: SharedSecretKey::new([56; 32], &recipient_keys.vpk()),
+                    ssk: SharedSecretKey::encapsulate_deterministic(
+                        &recipient_keys.vpk(),
+                        &[0_u8; 32],
+                        0,
+                    )
+                    .0,
                     identifier: 0,
                 },
             ],
@@ -2133,14 +2162,24 @@ pub mod tests {
             Program::serialize_instruction(10_u128).unwrap(),
             vec![
                 InputAccountIdentity::PrivateAuthorizedUpdate {
-                    ssk: SharedSecretKey::new([55; 32], &sender_keys.vpk()),
+                    ssk: SharedSecretKey::encapsulate_deterministic(
+                        &sender_keys.vpk(),
+                        &[0_u8; 32],
+                        0,
+                    )
+                    .0,
                     nsk: sender_keys.nsk,
                     membership_proof: (0, vec![]),
                     identifier: 0,
                 },
                 InputAccountIdentity::PrivateUnauthorized {
                     npk: recipient_keys.npk(),
-                    ssk: SharedSecretKey::new([56; 32], &recipient_keys.vpk()),
+                    ssk: SharedSecretKey::encapsulate_deterministic(
+                        &recipient_keys.vpk(),
+                        &[0_u8; 32],
+                        0,
+                    )
+                    .0,
                     identifier: 0,
                 },
             ],
@@ -2179,14 +2218,24 @@ pub mod tests {
             Program::serialize_instruction(10_u128).unwrap(),
             vec![
                 InputAccountIdentity::PrivateAuthorizedUpdate {
-                    ssk: SharedSecretKey::new([55; 32], &sender_keys.vpk()),
+                    ssk: SharedSecretKey::encapsulate_deterministic(
+                        &sender_keys.vpk(),
+                        &[0_u8; 32],
+                        0,
+                    )
+                    .0,
                     nsk: sender_keys.nsk,
                     membership_proof: (0, vec![]),
                     identifier: 0,
                 },
                 InputAccountIdentity::PrivateUnauthorized {
                     npk: recipient_keys.npk(),
-                    ssk: SharedSecretKey::new([56; 32], &recipient_keys.vpk()),
+                    ssk: SharedSecretKey::encapsulate_deterministic(
+                        &recipient_keys.vpk(),
+                        &[0_u8; 32],
+                        0,
+                    )
+                    .0,
                     identifier: 0,
                 },
             ],
@@ -2223,14 +2272,24 @@ pub mod tests {
             Program::serialize_instruction(10_u128).unwrap(),
             vec![
                 InputAccountIdentity::PrivateAuthorizedUpdate {
-                    ssk: SharedSecretKey::new([55; 32], &sender_keys.vpk()),
+                    ssk: SharedSecretKey::encapsulate_deterministic(
+                        &sender_keys.vpk(),
+                        &[0_u8; 32],
+                        0,
+                    )
+                    .0,
                     nsk: sender_keys.nsk,
                     membership_proof: (0, vec![]),
                     identifier: 0,
                 },
                 InputAccountIdentity::PrivateUnauthorized {
                     npk: recipient_keys.npk(),
-                    ssk: SharedSecretKey::new([56; 32], &recipient_keys.vpk()),
+                    ssk: SharedSecretKey::encapsulate_deterministic(
+                        &recipient_keys.vpk(),
+                        &[0_u8; 32],
+                        0,
+                    )
+                    .0,
                     identifier: 0,
                 },
             ],
@@ -2249,7 +2308,8 @@ pub mod tests {
         let program = Program::simple_balance_transfer();
         let keys = test_private_account_keys_1();
         let npk = keys.npk();
-        let shared_secret = SharedSecretKey::new([55; 32], &keys.vpk());
+        let shared_secret =
+            SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
         let public_account_1 = AccountWithMetadata::new(
             Account {
                 program_owner: program.id(),
@@ -2291,7 +2351,8 @@ pub mod tests {
         let keys = test_private_account_keys_1();
         let npk = keys.npk();
         let seed = PdaSeed::new([42; 32]);
-        let shared_secret = SharedSecretKey::new([55; 32], &keys.vpk());
+        let shared_secret =
+            SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
 
         let account_id = AccountId::for_private_pda(&program.id(), &seed, &npk, u128::MAX);
         let pre_state = AccountWithMetadata::new(Account::default(), false, account_id);
@@ -2328,7 +2389,8 @@ pub mod tests {
         let npk_a = keys_a.npk();
         let npk_b = keys_b.npk();
         let seed = PdaSeed::new([42; 32]);
-        let shared_secret = SharedSecretKey::new([55; 32], &keys_b.vpk());
+        let shared_secret =
+            SharedSecretKey::encapsulate_deterministic(&keys_b.vpk(), &[0_u8; 32], 0).0;
 
         // `account_id` is derived from `npk_a`, but `npk_b` is supplied for this pre_state.
         // `AccountId::for_private_pda(program, seed, npk_b) != account_id`, so the claim check in
@@ -2363,7 +2425,8 @@ pub mod tests {
         let keys = test_private_account_keys_1();
         let npk = keys.npk();
         let seed = PdaSeed::new([77; 32]);
-        let shared_secret = SharedSecretKey::new([55; 32], &keys.vpk());
+        let shared_secret =
+            SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
 
         let account_id = AccountId::for_private_pda(&delegator.id(), &seed, &npk, u128::MAX);
         let pre_state = AccountWithMetadata::new(Account::default(), false, account_id);
@@ -2402,7 +2465,8 @@ pub mod tests {
         let npk = keys.npk();
         let claim_seed = PdaSeed::new([77; 32]);
         let wrong_delegated_seed = PdaSeed::new([88; 32]);
-        let shared_secret = SharedSecretKey::new([55; 32], &keys.vpk());
+        let shared_secret =
+            SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
 
         let account_id = AccountId::for_private_pda(&delegator.id(), &claim_seed, &npk, u128::MAX);
         let pre_state = AccountWithMetadata::new(Account::default(), false, account_id);
@@ -2440,8 +2504,8 @@ pub mod tests {
         let keys_a = test_private_account_keys_1();
         let keys_b = test_private_account_keys_2();
         let seed = PdaSeed::new([55; 32]);
-        let shared_a = SharedSecretKey::new([66; 32], &keys_a.vpk());
-        let shared_b = SharedSecretKey::new([77; 32], &keys_b.vpk());
+        let shared_a = SharedSecretKey::encapsulate_deterministic(&keys_a.vpk(), &[0_u8; 32], 0).0;
+        let shared_b = SharedSecretKey::encapsulate_deterministic(&keys_b.vpk(), &[0_u8; 32], 0).0;
 
         let account_a = AccountId::for_private_pda(&program.id(), &seed, &keys_a.npk(), u128::MAX);
         let account_b = AccountId::for_private_pda(&program.id(), &seed, &keys_b.npk(), u128::MAX);
@@ -2482,7 +2546,8 @@ pub mod tests {
         let program = Program::noop();
         let keys = test_private_account_keys_1();
         let npk = keys.npk();
-        let shared_secret = SharedSecretKey::new([55; 32], &keys.vpk());
+        let shared_secret =
+            SharedSecretKey::encapsulate_deterministic(&keys.vpk(), &[0_u8; 32], 0).0;
         let seed = PdaSeed::new([99; 32]);
 
         // Simulate a previously-claimed private PDA: program_owner != DEFAULT, is_authorized =
@@ -2582,7 +2647,8 @@ pub mod tests {
             (&sender_keys.npk(), 0),
         );
 
-        let shared_secret = SharedSecretKey::new([55; 32], &sender_keys.vpk());
+        let shared_secret =
+            SharedSecretKey::encapsulate_deterministic(&sender_keys.vpk(), &[0_u8; 32], 0).0;
         let result = execute_and_prove(
             vec![private_account_1.clone(), private_account_1],
             Program::serialize_instruction(100_u128).unwrap(),
@@ -2926,9 +2992,8 @@ pub mod tests {
             AccountId::from(&PublicKey::new_from_private_key(&recipient_private_key));
         let recipient_pre =
             AccountWithMetadata::new(Account::default(), true, recipient_account_id);
-        let esk = [5; 32];
-        let shared_secret = SharedSecretKey::new(esk, &sender_keys.vpk());
-        let epk = EphemeralPublicKey::from_scalar(esk);
+        let (shared_secret, epk) =
+            SharedSecretKey::encapsulate_deterministic(&sender_keys.vpk(), &[0_u8; 32], 0);
 
         let balance = 37;
 
@@ -3032,13 +3097,11 @@ pub mod tests {
             None,
         );
 
-        let from_esk = [3; 32];
-        let from_ss = SharedSecretKey::new(from_esk, &from_keys.vpk());
-        let from_epk = EphemeralPublicKey::from_scalar(from_esk);
+        let (from_ss, from_epk) =
+            SharedSecretKey::encapsulate_deterministic(&from_keys.vpk(), &[0_u8; 32], 0);
 
-        let to_esk = [3; 32];
-        let to_ss = SharedSecretKey::new(to_esk, &to_keys.vpk());
-        let to_epk = EphemeralPublicKey::from_scalar(to_esk);
+        let (to_ss, to_epk) =
+            SharedSecretKey::encapsulate_deterministic(&to_keys.vpk(), &[0_u8; 32], 1);
 
         let mut dependencies = HashMap::new();
 
@@ -3335,9 +3398,8 @@ pub mod tests {
         let program = Program::authenticated_transfer_program();
 
         // Set up parameters for the new account
-        let esk = [3; 32];
-        let shared_secret = SharedSecretKey::new(esk, &private_keys.vpk());
-        let epk = EphemeralPublicKey::from_scalar(esk);
+        let (shared_secret, epk) =
+            SharedSecretKey::encapsulate_deterministic(&private_keys.vpk(), &[0_u8; 32], 0);
 
         let instruction = authenticated_transfer_core::Instruction::Initialize;
 
@@ -3387,9 +3449,8 @@ pub mod tests {
             AccountWithMetadata::new(Account::default(), false, (&private_keys.npk(), 0));
 
         let program = Program::claimer();
-        let esk = [5; 32];
-        let shared_secret = SharedSecretKey::new(esk, &private_keys.vpk());
-        let epk = EphemeralPublicKey::from_scalar(esk);
+        let (shared_secret, epk) =
+            SharedSecretKey::encapsulate_deterministic(&private_keys.vpk(), &[0_u8; 32], 0);
 
         let (output, proof) = execute_and_prove(
             vec![unauthorized_account],
@@ -3437,9 +3498,8 @@ pub mod tests {
         let claimer_program = Program::claimer();
 
         // Set up parameters for claiming the new account
-        let esk = [3; 32];
-        let shared_secret = SharedSecretKey::new(esk, &private_keys.vpk());
-        let epk = EphemeralPublicKey::from_scalar(esk);
+        let (shared_secret, epk) =
+            SharedSecretKey::encapsulate_deterministic(&private_keys.vpk(), &[0_u8; 32], 0);
 
         let instruction = authenticated_transfer_core::Instruction::Initialize;
 
@@ -3487,8 +3547,8 @@ pub mod tests {
         };
 
         let noop_program = Program::noop();
-        let esk2 = [4; 32];
-        let shared_secret2 = SharedSecretKey::new(esk2, &private_keys.vpk());
+        let shared_secret2 =
+            SharedSecretKey::encapsulate_deterministic(&private_keys.vpk(), &[0_u8; 32], 0).0;
 
         // Step 3: Try to execute noop program with authentication but without initialization
         let res = execute_and_prove(
@@ -3572,7 +3632,8 @@ pub mod tests {
             vec![private_account],
             Program::serialize_instruction(instruction).unwrap(),
             vec![InputAccountIdentity::PrivateAuthorizedUpdate {
-                ssk: SharedSecretKey::new([3; 32], &sender_keys.vpk()),
+                ssk: SharedSecretKey::encapsulate_deterministic(&sender_keys.vpk(), &[0_u8; 32], 0)
+                    .0,
                 nsk: sender_keys.nsk,
                 membership_proof: (0, vec![]),
                 identifier: 0,
@@ -3598,7 +3659,8 @@ pub mod tests {
             vec![private_account],
             Program::serialize_instruction(instruction).unwrap(),
             vec![InputAccountIdentity::PrivateAuthorizedUpdate {
-                ssk: SharedSecretKey::new([3; 32], &sender_keys.vpk()),
+                ssk: SharedSecretKey::encapsulate_deterministic(&sender_keys.vpk(), &[0_u8; 32], 0)
+                    .0,
                 nsk: sender_keys.nsk,
                 membership_proof: (0, vec![]),
                 identifier: 0,
@@ -3644,8 +3706,8 @@ pub mod tests {
         let balance_to_transfer = 10_u128;
         let instruction = (balance_to_transfer, auth_transfers.id());
 
-        let recipient_esk = [3; 32];
-        let recipient = SharedSecretKey::new(recipient_esk, &recipient_keys.vpk());
+        let recipient =
+            SharedSecretKey::encapsulate_deterministic(&recipient_keys.vpk(), &[0_u8; 32], 0).0;
 
         let mut dependencies = HashMap::new();
         dependencies.insert(auth_transfers.id(), auth_transfers);
@@ -3801,9 +3863,8 @@ pub mod tests {
         let pre = AccountWithMetadata::new(Account::default(), false, (&account_keys.npk(), 0));
         let mut state = V03State::new_with_genesis_accounts(&[], vec![], 0).with_test_programs();
         let tx = {
-            let esk = [3; 32];
-            let shared_secret = SharedSecretKey::new(esk, &account_keys.vpk());
-            let epk = EphemeralPublicKey::from_scalar(esk);
+            let (shared_secret, epk) =
+                SharedSecretKey::encapsulate_deterministic(&account_keys.vpk(), &[0_u8; 32], 0);
 
             let instruction = (
                 block_validity_window,
@@ -3871,9 +3932,8 @@ pub mod tests {
         let pre = AccountWithMetadata::new(Account::default(), false, (&account_keys.npk(), 0));
         let mut state = V03State::new_with_genesis_accounts(&[], vec![], 0).with_test_programs();
         let tx = {
-            let esk = [3; 32];
-            let shared_secret = SharedSecretKey::new(esk, &account_keys.vpk());
-            let epk = EphemeralPublicKey::from_scalar(esk);
+            let (shared_secret, epk) =
+                SharedSecretKey::encapsulate_deterministic(&account_keys.vpk(), &[0_u8; 32], 0);
 
             let instruction = (
                 BlockValidityWindow::new_unbounded(),
@@ -4427,8 +4487,10 @@ pub mod tests {
             ..Account::default()
         };
 
-        let alice_shared_0 = SharedSecretKey::new([10; 32], &alice_keys.vpk());
-        let alice_shared_1 = SharedSecretKey::new([11; 32], &alice_keys.vpk());
+        let (alice_shared_0, alice_epk_0) =
+            SharedSecretKey::encapsulate_deterministic(&alice_keys.vpk(), &[0_u8; 32], 0);
+        let (alice_shared_1, alice_epk_1) =
+            SharedSecretKey::encapsulate_deterministic(&alice_keys.vpk(), &[0_u8; 32], 1);
 
         // Fund alice_pda_0 via authenticated_transfer directly.
         {
@@ -4456,11 +4518,7 @@ pub mod tests {
             let message = Message::try_from_circuit_output(
                 vec![funder_id],
                 vec![funder_nonce],
-                vec![(
-                    alice_npk,
-                    alice_keys.vpk(),
-                    EphemeralPublicKey::from_scalar([10; 32]),
-                )],
+                vec![(alice_npk, alice_keys.vpk(), alice_epk_0.clone())],
                 output,
             )
             .unwrap();
@@ -4500,11 +4558,7 @@ pub mod tests {
             let message = Message::try_from_circuit_output(
                 vec![funder_id],
                 vec![funder_nonce],
-                vec![(
-                    alice_npk,
-                    alice_keys.vpk(),
-                    EphemeralPublicKey::from_scalar([11; 32]),
-                )],
+                vec![(alice_npk, alice_keys.vpk(), alice_epk_1.clone())],
                 output,
             )
             .unwrap();
@@ -4551,11 +4605,7 @@ pub mod tests {
             let message = Message::try_from_circuit_output(
                 vec![recipient_id],
                 vec![Nonce(0)],
-                vec![(
-                    alice_npk,
-                    alice_keys.vpk(),
-                    EphemeralPublicKey::from_scalar([10; 32]),
-                )],
+                vec![(alice_npk, alice_keys.vpk(), alice_epk_0)],
                 output,
             )
             .unwrap();
@@ -4596,11 +4646,7 @@ pub mod tests {
             let message = Message::try_from_circuit_output(
                 vec![recipient_id],
                 vec![],
-                vec![(
-                    alice_npk,
-                    alice_keys.vpk(),
-                    EphemeralPublicKey::from_scalar([11; 32]),
-                )],
+                vec![(alice_npk, alice_keys.vpk(), alice_epk_1)],
                 output,
             )
             .unwrap();
@@ -4628,7 +4674,7 @@ pub mod tests {
         };
         let commitment_pda_1_after_spend =
             Commitment::new(&alice_pda_1_id, &alice_pda_1_account_after_spend);
-        let alice_shared_1_refund = SharedSecretKey::new([12; 32], &alice_keys.vpk());
+        let alice_shared_1_refund = SharedSecretKey([12; 32]);
         {
             let recipient_account = state.get_account_by_id(recipient_id);
             let recipient_nonce = recipient_account.nonce;
@@ -4664,7 +4710,7 @@ pub mod tests {
                 vec![(
                     alice_npk,
                     alice_keys.vpk(),
-                    EphemeralPublicKey::from_scalar([12; 32]),
+                    EphemeralPublicKey(vec![12_u8; 1088]),
                 )],
                 output,
             )
diff --git a/nssa/src/validated_state_diff.rs b/nssa/src/validated_state_diff.rs
index bdee3452..4a494507 100644
--- a/nssa/src/validated_state_diff.rs
+++ b/nssa/src/validated_state_diff.rs
@@ -544,7 +544,6 @@ mod tests {
         use nssa_core::{
             Commitment, InputAccountIdentity, SharedSecretKey,
             account::{Account, AccountWithMetadata},
-            encryption::EphemeralPublicKey,
         };
 
         use crate::{
@@ -571,9 +570,7 @@ mod tests {
         // Attacker controls a private account.
         let attacker_keys = test_private_account_keys_1();
         let attacker_id = AccountId::for_regular_private_account(&attacker_keys.npk(), 0);
-        let attacker_esk = [12_u8; 32];
-        let attacker_ssk = SharedSecretKey::new(attacker_esk, &attacker_keys.vpk());
-        let attacker_epk = EphemeralPublicKey::from_scalar(attacker_esk);
+        let (attacker_ssk, attacker_epk) = SharedSecretKey::encapsulate(&attacker_keys.vpk());
 
         let victim_id = AccountId::new([20_u8; 32]);
         let recipient_id = AccountId::new([42_u8; 32]);
@@ -695,7 +692,6 @@ mod tests {
         use nssa_core::{
             Commitment, InputAccountIdentity, SharedSecretKey,
             account::{Account, AccountWithMetadata},
-            encryption::EphemeralPublicKey,
         };
 
         use crate::{
@@ -725,9 +721,7 @@ mod tests {
         // Attacker controls a private account.
         let attacker_keys = test_private_account_keys_1();
         let attacker_id = AccountId::for_regular_private_account(&attacker_keys.npk(), 0);
-        let attacker_esk = [12_u8; 32];
-        let attacker_ssk = SharedSecretKey::new(attacker_esk, &attacker_keys.vpk());
-        let attacker_epk = EphemeralPublicKey::from_scalar(attacker_esk);
+        let (attacker_ssk, attacker_epk) = SharedSecretKey::encapsulate(&attacker_keys.vpk());
 
         // Victim is a private account — not registered in public chain state.
         let victim_keys = test_private_account_keys_2();
diff --git a/testnet_initial_state/src/lib.rs b/testnet_initial_state/src/lib.rs
index 668d5f24..eac658fd 100644
--- a/testnet_initial_state/src/lib.rs
+++ b/testnet_initial_state/src/lib.rs
@@ -2,10 +2,10 @@ use common::PINATA_BASE58;
 use key_protocol::key_management::{
     KeyChain,
     key_tree::chain_index::ChainIndex,
-    secret_holders::{PrivateKeyHolder, SecretSpendingKey},
+    secret_holders::{PrivateKeyHolder, SecretSpendingKey, ViewingSecretKey},
 };
 use nssa::{Account, AccountId, Data, PrivateKey, PublicKey, V03State};
-use nssa_core::{NullifierPublicKey, encryption::shared_key_derivation::Secp256k1Point};
+use nssa_core::{NullifierPublicKey, encryption::ViewingPublicKey};
 use serde::{Deserialize, Serialize};
 
 const PRIVATE_KEY_PUB_ACC_A: [u8; 32] = [
@@ -38,24 +38,24 @@ const NSK_PRIV_ACC_B: [u8; 32] = [
     23, 99, 9, 4, 177, 230, 125, 109, 91, 160, 30,
 ];
 
-const VSK_PRIV_ACC_A: [u8; 32] = [
-    5, 85, 114, 119, 141, 187, 202, 170, 122, 253, 198, 81, 150, 8, 155, 21, 192, 65, 24, 124, 116,
-    98, 110, 106, 137, 90, 165, 239, 80, 13, 222, 30,
+const VSK_D_PRIV_ACC_A: [u8; 32] = [
+    255, 250, 140, 26, 222, 223, 174, 95, 132, 108, 124, 88, 30, 247, 82, 72, 52, 70, 84, 139, 241,
+    187, 41, 163, 19, 231, 232, 122, 225, 55, 134, 184,
 ];
 
-const VSK_PRIV_ACC_B: [u8; 32] = [
-    205, 32, 76, 251, 255, 236, 96, 119, 61, 111, 65, 100, 75, 218, 12, 22, 17, 170, 55, 226, 21,
-    154, 161, 34, 208, 74, 27, 1, 119, 13, 88, 128,
+const VSK_Z_PRIV_ACC_A: [u8; 32] = [
+    225, 24, 98, 78, 31, 203, 175, 248, 213, 17, 133, 207, 10, 135, 132, 151, 59, 184, 5, 81, 28,
+    238, 137, 62, 233, 227, 99, 17, 236, 159, 244, 63,
 ];
 
-const VPK_PRIV_ACC_A: [u8; 33] = [
-    2, 210, 206, 38, 213, 4, 182, 198, 220, 47, 93, 148, 61, 84, 148, 250, 158, 45, 8, 81, 48, 80,
-    46, 230, 87, 210, 47, 204, 76, 58, 214, 167, 81,
+const VSK_D_PRIV_ACC_B: [u8; 32] = [
+    128, 85, 85, 103, 226, 218, 119, 56, 60, 252, 31, 113, 232, 215, 156, 2, 159, 247, 156, 192,
+    12, 178, 229, 236, 255, 120, 146, 211, 169, 117, 153, 180,
 ];
 
-const VPK_PRIV_ACC_B: [u8; 33] = [
-    2, 79, 110, 46, 203, 29, 206, 205, 18, 86, 27, 189, 104, 103, 113, 181, 110, 53, 78, 172, 11,
-    171, 190, 18, 126, 214, 81, 77, 192, 154, 58, 195, 238,
+const VSK_Z_PRIV_ACC_B: [u8; 32] = [
+    165, 80, 169, 87, 248, 88, 167, 154, 27, 67, 131, 122, 50, 130, 111, 40, 164, 180, 204, 75,
+    188, 140, 110, 132, 113, 133, 222, 8, 49, 123, 187, 18,
 ];
 
 const NPK_PRIV_ACC_A: [u8; 32] = [
@@ -136,20 +136,20 @@ pub fn initial_priv_accounts_private_keys() -> Vec<PrivateAccountPrivateInitialD
         secret_spending_key: SecretSpendingKey(SSK_PRIV_ACC_A),
         private_key_holder: PrivateKeyHolder {
             nullifier_secret_key: NSK_PRIV_ACC_A,
-            viewing_secret_key: VSK_PRIV_ACC_A,
+            viewing_secret_key: ViewingSecretKey::new(VSK_D_PRIV_ACC_A, VSK_Z_PRIV_ACC_A),
         },
         nullifier_public_key: NullifierPublicKey(NPK_PRIV_ACC_A),
-        viewing_public_key: Secp256k1Point(VPK_PRIV_ACC_A.to_vec()),
+        viewing_public_key: ViewingPublicKey::from_seed(&VSK_D_PRIV_ACC_A, &VSK_Z_PRIV_ACC_A),
     };
 
     let key_chain_2 = KeyChain {
         secret_spending_key: SecretSpendingKey(SSK_PRIV_ACC_B),
         private_key_holder: PrivateKeyHolder {
             nullifier_secret_key: NSK_PRIV_ACC_B,
-            viewing_secret_key: VSK_PRIV_ACC_B,
+            viewing_secret_key: ViewingSecretKey::new(VSK_D_PRIV_ACC_B, VSK_Z_PRIV_ACC_B),
         },
         nullifier_public_key: NullifierPublicKey(NPK_PRIV_ACC_B),
-        viewing_public_key: Secp256k1Point(VPK_PRIV_ACC_B.to_vec()),
+        viewing_public_key: ViewingPublicKey::from_seed(&VSK_D_PRIV_ACC_B, &VSK_Z_PRIV_ACC_B),
     };
 
     vec![
diff --git a/tools/crypto_primitives_bench/Cargo.toml b/tools/crypto_primitives_bench/Cargo.toml
index 8e99f79f..b70e79c4 100644
--- a/tools/crypto_primitives_bench/Cargo.toml
+++ b/tools/crypto_primitives_bench/Cargo.toml
@@ -11,6 +11,10 @@ workspace = true
 [dev-dependencies]
 key_protocol.workspace = true
 nssa_core = { workspace = true, features = ["host"] }
+
+anyhow.workspace = true
+serde.workspace = true
+serde_json.workspace = true
 rand = { workspace = true }
 criterion.workspace = true
 
diff --git a/tools/crypto_primitives_bench/benches/primitives.rs b/tools/crypto_primitives_bench/benches/primitives.rs
index cfa0858f..1264fe53 100644
--- a/tools/crypto_primitives_bench/benches/primitives.rs
+++ b/tools/crypto_primitives_bench/benches/primitives.rs
@@ -3,7 +3,7 @@
 //! Measures:
 //! - `KeyChain::new_os_random` (mnemonic → SSK → NSK/VSK + public keys)
 //! - `KeyChain::new_mnemonic` (same, but mnemonic exposed)
-//! - `SharedSecretKey::new` (Diffie-Hellman shared key derivation, the per-recipient cost)
+//! - `SharedSecretKey::encapsulate` (ML-KEM-768 encapsulation, the per-recipient cost)
 //! - `EncryptionScheme::encrypt` / `decrypt` (Account note encryption)
 
 use std::time::Duration;
@@ -13,10 +13,8 @@ use key_protocol::key_management::KeyChain;
 use nssa_core::{
     Commitment, EncryptionScheme, SharedSecretKey,
     account::{Account, AccountId},
-    encryption::{EphemeralPublicKey, EphemeralSecretKey},
     program::PrivateAccountKind,
 };
-use rand::{RngCore as _, rngs::OsRng};
 
 fn bench_keychain(c: &mut Criterion) {
     let mut g = c.benchmark_group("keychain");
@@ -37,34 +35,22 @@ fn bench_shared_secret_key(c: &mut Criterion) {
 
     let mut g = c.benchmark_group("shared_secret_key");
     g.sample_size(50).noise_threshold(0.05);
-    g.bench_function("sender_dh", |b| {
-        b.iter(|| {
-            let mut bytes = [0_u8; 32];
-            OsRng.fill_bytes(&mut bytes);
-            let esk: EphemeralSecretKey = bytes;
-            let _epk = EphemeralPublicKey::from(&esk);
-            SharedSecretKey::new(esk, &vpk)
-        });
+    g.bench_function("sender_encapsulate", |b| {
+        b.iter(|| SharedSecretKey::encapsulate(&vpk));
     });
     g.finish();
 }
 
 fn bench_encryption(c: &mut Criterion) {
     // One-time setup: a fixed Account/Commitment and a SharedSecretKey to bench
-    // encrypt/decrypt over a representative note. ESK gen is excluded from the
-    // measured loop (covered by the SharedSecretKey bench above).
+    // encrypt/decrypt over a representative note. Encapsulation cost is covered
+    // by the SharedSecretKey bench above.
     let recipient_kc = KeyChain::new_os_random();
-    let vpk = recipient_kc.viewing_public_key;
     let npk = recipient_kc.nullifier_public_key;
     let account = Account::default();
     let account_id = AccountId::for_regular_private_account(&npk, 0);
     let commitment = Commitment::new(&account_id, &account);
-    let shared = {
-        let mut bytes = [0_u8; 32];
-        OsRng.fill_bytes(&mut bytes);
-        let esk: EphemeralSecretKey = bytes;
-        SharedSecretKey::new(esk, &vpk)
-    };
+    let (shared, _epk) = SharedSecretKey::encapsulate(&recipient_kc.viewing_public_key);
     let kind = PrivateAccountKind::Regular(0_u128);
     let output_index: u32 = 0;
 
@@ -73,7 +59,6 @@ fn bench_encryption(c: &mut Criterion) {
     g.bench_function("encrypt", |b| {
         b.iter(|| EncryptionScheme::encrypt(&account, &kind, &shared, &commitment, output_index));
     });
-    // One ciphertext for the decrypt bench (encrypt is deterministic given inputs).
     let ct = EncryptionScheme::encrypt(&account, &kind, &shared, &commitment, output_index);
     g.bench_function("decrypt", |b| {
         b.iter(|| EncryptionScheme::decrypt(&ct, &shared, &commitment, output_index));
diff --git a/tools/integration_bench/src/scenarios/amm.rs b/tools/integration_bench/src/scenarios/amm.rs
index 79100c42..a1b8395a 100644
--- a/tools/integration_bench/src/scenarios/amm.rs
+++ b/tools/integration_bench/src/scenarios/amm.rs
@@ -180,6 +180,7 @@ async fn timed_token_send(
                     to: Some(public_mention(to_id)),
                     to_npk: None,
                     to_vpk: None,
+                    to_keys: None,
                     to_identifier: Some(0),
                     amount,
                 }),
diff --git a/tools/integration_bench/src/scenarios/fanout.rs b/tools/integration_bench/src/scenarios/fanout.rs
index d03adf83..6090ba97 100644
--- a/tools/integration_bench/src/scenarios/fanout.rs
+++ b/tools/integration_bench/src/scenarios/fanout.rs
@@ -50,6 +50,7 @@ pub async fn run(ctx: &mut TestContext) -> Result<ScenarioOutput> {
                         to: Some(public_mention(recipient_id)),
                         to_npk: None,
                         to_vpk: None,
+                        to_keys: None,
                         to_identifier: Some(0),
                         amount: AMOUNT_PER_TRANSFER,
                     }),
diff --git a/tools/integration_bench/src/scenarios/parallel.rs b/tools/integration_bench/src/scenarios/parallel.rs
index c6a265b9..da908bde 100644
--- a/tools/integration_bench/src/scenarios/parallel.rs
+++ b/tools/integration_bench/src/scenarios/parallel.rs
@@ -69,6 +69,7 @@ pub async fn run(ctx: &mut TestContext) -> Result<ScenarioOutput> {
                         to: Some(public_mention(sender_id)),
                         to_npk: None,
                         to_vpk: None,
+                        to_keys: None,
                         to_identifier: Some(0),
                         amount: AMOUNT_PER_TRANSFER * 5,
                     }),
@@ -97,6 +98,7 @@ pub async fn run(ctx: &mut TestContext) -> Result<ScenarioOutput> {
                 to: Some(public_mention(*recipient_id)),
                 to_npk: None,
                 to_vpk: None,
+                to_keys: None,
                 to_identifier: Some(0),
                 amount: AMOUNT_PER_TRANSFER,
             }),
diff --git a/tools/integration_bench/src/scenarios/private.rs b/tools/integration_bench/src/scenarios/private.rs
index 2be8c43c..e8293870 100644
--- a/tools/integration_bench/src/scenarios/private.rs
+++ b/tools/integration_bench/src/scenarios/private.rs
@@ -46,6 +46,7 @@ pub async fn run(ctx: &mut TestContext) -> Result<ScenarioOutput> {
                     to: Some(private_mention(private_a)),
                     to_npk: None,
                     to_vpk: None,
+                    to_keys: None,
                     to_identifier: Some(0),
                     amount: 1_000,
                 }),
@@ -64,6 +65,7 @@ pub async fn run(ctx: &mut TestContext) -> Result<ScenarioOutput> {
                     to: Some(public_mention(public_recipient_id)),
                     to_npk: None,
                     to_vpk: None,
+                    to_keys: None,
                     to_identifier: Some(0),
                     amount: 100,
                 }),
@@ -82,6 +84,7 @@ pub async fn run(ctx: &mut TestContext) -> Result<ScenarioOutput> {
                     to: Some(private_mention(private_b)),
                     to_npk: None,
                     to_vpk: None,
+                    to_keys: None,
                     to_identifier: Some(0),
                     amount: 200,
                 }),
diff --git a/tools/integration_bench/src/scenarios/token.rs b/tools/integration_bench/src/scenarios/token.rs
index d1dfdef3..bd628b86 100644
--- a/tools/integration_bench/src/scenarios/token.rs
+++ b/tools/integration_bench/src/scenarios/token.rs
@@ -41,6 +41,7 @@ pub async fn run(ctx: &mut TestContext) -> Result<ScenarioOutput> {
                     to: Some(public_mention(recipient_id)),
                     to_npk: None,
                     to_vpk: None,
+                    to_keys: None,
                     to_identifier: Some(0),
                     amount: 1_000,
                 }),
@@ -61,6 +62,7 @@ pub async fn run(ctx: &mut TestContext) -> Result<ScenarioOutput> {
                     to: Some(private_mention(private_recipient_id)),
                     to_npk: None,
                     to_vpk: None,
+                    to_keys: None,
                     to_identifier: Some(0),
                     amount: 500,
                 }),
diff --git a/wallet-ffi/src/keys.rs b/wallet-ffi/src/keys.rs
index b676ffab..68f952cb 100644
--- a/wallet-ffi/src/keys.rs
+++ b/wallet-ffi/src/keys.rs
@@ -125,7 +125,7 @@ pub unsafe extern "C" fn wallet_ffi_get_private_account_keys(
     // NPK is a 32-byte array
     let npk_bytes = key_chain.nullifier_public_key.0;
 
-    // VPK is a compressed secp256k1 point (33 bytes)
+    // VPK is an ML-KEM-768 encapsulation key (1184 bytes)
     let vpk_bytes = key_chain.viewing_public_key.to_bytes();
     let vpk_len = vpk_bytes.len();
     let vpk_vec = vpk_bytes.to_vec();
diff --git a/wallet-ffi/src/types.rs b/wallet-ffi/src/types.rs
index b970a8d3..554f04b7 100644
--- a/wallet-ffi/src/types.rs
+++ b/wallet-ffi/src/types.rs
@@ -4,7 +4,6 @@ use core::slice;
 use std::{ffi::c_char, ptr};
 
 use nssa::Data;
-use nssa_core::encryption::shared_key_derivation::Secp256k1Point;
 
 use crate::error::WalletFfiError;
 
@@ -72,9 +71,9 @@ impl Default for FfiAccount {
 pub struct FfiPrivateAccountKeys {
     /// Nullifier public key (32 bytes).
     pub nullifier_public_key: FfiBytes32,
-    /// viewing public key (compressed secp256k1 point).
+    /// Viewing public key (ML-KEM-768 encapsulation key, 1184 bytes).
     pub viewing_public_key: *const u8,
-    /// Length of viewing public key (typically 33 bytes).
+    /// Length of viewing public key (always 1184 bytes for ML-KEM-768).
     pub viewing_public_key_len: usize,
 }
 
@@ -161,11 +160,15 @@ impl FfiPrivateAccountKeys {
     }
 
     pub fn vpk(&self) -> Result<nssa_core::encryption::ViewingPublicKey, WalletFfiError> {
-        if self.viewing_public_key_len == 33 {
+        if self.viewing_public_key_len == 1184 {
             let slice = unsafe {
                 slice::from_raw_parts(self.viewing_public_key, self.viewing_public_key_len)
             };
-            Ok(Secp256k1Point(slice.to_vec()))
+            Ok(
+                nssa_core::encryption::MlKem768EncapsulationKey::from_bytes(slice.to_vec()).expect(
+                    "wallet_ffi::types::FfiPrivateAccountKeys::vpk: length already validated above",
+                ),
+            )
         } else {
             Err(WalletFfiError::InvalidKeyValue)
         }
diff --git a/wallet-ffi/wallet_ffi.h b/wallet-ffi/wallet_ffi.h
index adbb7b50..8994fca0 100644
--- a/wallet-ffi/wallet_ffi.h
+++ b/wallet-ffi/wallet_ffi.h
@@ -135,11 +135,11 @@ typedef struct FfiPrivateAccountKeys {
    */
   struct FfiBytes32 nullifier_public_key;
   /**
-   * viewing public key (compressed secp256k1 point).
+   * Viewing public key (ML-KEM-768 encapsulation key, 1184 bytes).
    */
   const uint8_t *viewing_public_key;
   /**
-   * Length of viewing public key (typically 33 bytes).
+   * Length of viewing public key (always 1184 bytes for ML-KEM-768).
    */
   uintptr_t viewing_public_key_len;
 } FfiPrivateAccountKeys;
diff --git a/wallet/src/account_manager.rs b/wallet/src/account_manager.rs
index 5caf2b22..67c4d939 100644
--- a/wallet/src/account_manager.rs
+++ b/wallet/src/account_manager.rs
@@ -136,9 +136,9 @@ impl AccountManager {
                 } => {
                     let acc = nssa_core::account::Account::default();
                     let auth_acc = AccountWithMetadata::new(acc, false, (&npk, identifier));
-                    let eph_holder = EphemeralKeyHolder::new(&npk);
-                    let ssk = eph_holder.calculate_shared_secret_sender(&vpk);
-                    let epk = eph_holder.generate_ephemeral_public_key();
+                    let eph_holder = EphemeralKeyHolder::new(&vpk);
+                    let ssk = eph_holder.calculate_shared_secret_sender();
+                    let epk = eph_holder.ephemeral_public_key().clone();
                     let pre = AccountPreparedData {
                         nsk: None,
                         npk,
@@ -165,9 +165,9 @@ impl AccountManager {
                 } => {
                     let acc = nssa_core::account::Account::default();
                     let auth_acc = AccountWithMetadata::new(acc, false, account_id);
-                    let eph_holder = EphemeralKeyHolder::new(&npk);
-                    let ssk = eph_holder.calculate_shared_secret_sender(&vpk);
-                    let epk = eph_holder.generate_ephemeral_public_key();
+                    let eph_holder = EphemeralKeyHolder::new(&vpk);
+                    let ssk = eph_holder.calculate_shared_secret_sender();
+                    let epk = eph_holder.ephemeral_public_key().clone();
                     let pre = AccountPreparedData {
                         nsk: None,
                         npk,
@@ -365,9 +365,9 @@ async fn private_key_tree_acc_preparation(
     // support from that in the wallet.
     let sender_pre = AccountWithMetadata::new(from_acc.account.clone(), true, account_id);
 
-    let eph_holder = EphemeralKeyHolder::new(&from_npk);
-    let ssk = eph_holder.calculate_shared_secret_sender(&from_vpk);
-    let epk = eph_holder.generate_ephemeral_public_key();
+    let eph_holder = EphemeralKeyHolder::new(&from_vpk);
+    let ssk = eph_holder.calculate_shared_secret_sender();
+    let epk = eph_holder.ephemeral_public_key().clone();
 
     Ok(AccountPreparedData {
         nsk: Some(nsk),
@@ -405,9 +405,10 @@ async fn private_shared_acc_preparation(
         .await
         .unwrap_or(None);
 
-    let eph_holder = EphemeralKeyHolder::new(&npk);
-    let ssk = eph_holder.calculate_shared_secret_sender(&vpk);
-    let epk = eph_holder.generate_ephemeral_public_key();
+    let eph_holder = EphemeralKeyHolder::new(&vpk);
+    let ssk = eph_holder.calculate_shared_secret_sender();
+    let epk = eph_holder.ephemeral_public_key().clone();
+
     Ok(AccountPreparedData {
         nsk: Some(nsk),
         npk,
@@ -430,7 +431,7 @@ mod tests {
         let acc = AccountIdentity::PrivateShared {
             nsk: [0; 32],
             npk: NullifierPublicKey([1; 32]),
-            vpk: ViewingPublicKey::from_scalar([2; 32]),
+            vpk: ViewingPublicKey::from_seed(&[2_u8; 32], &[3_u8; 32]),
             identifier: 42,
         };
         assert!(acc.is_private());
diff --git a/wallet/src/cli/account.rs b/wallet/src/cli/account.rs
index 1dcea1d5..eec9440d 100644
--- a/wallet/src/cli/account.rs
+++ b/wallet/src/cli/account.rs
@@ -51,6 +51,20 @@ pub enum AccountSubcommand {
     /// Import external account.
     #[command(subcommand)]
     Import(ImportSubcommand),
+    /// Print the npk and vpk for a private account, one per line.
+    ///
+    /// Outputs two lines: npk (hex) then vpk (hex). Save to a file and share it
+    /// with senders so they can reference it with `--to-keys /path/to/file`.
+    ///
+    /// ```text
+    /// wallet account show-keys --account-id Private/... > alice.keys
+    /// ```
+    #[command(name = "show-keys")]
+    ShowKeys {
+        /// Either 32 byte base58 account id string with privacy prefix or a label.
+        #[arg(long)]
+        account_id: CliAccountMention,
+    },
 }
 
 /// Represents generic register CLI subcommand.
@@ -225,7 +239,7 @@ impl WalletSubcommand for NewSubcommand {
                 println!("Shared account from group '{group}'");
                 println!("AccountId: Private/{}", info.account_id);
                 println!("NPK: {}", hex::encode(info.npk.0));
-                println!("VPK: {}", hex::encode(&info.vpk.0));
+                println!("VPK: {}", hex::encode(info.vpk.to_bytes()));
 
                 wallet_core.store_persistent_data()?;
                 Ok(SubcommandReturnValue::RegisterAccount {
@@ -419,6 +433,25 @@ impl WalletSubcommand for AccountSubcommand {
             Self::Import(import_subcommand) => {
                 import_subcommand.handle_subcommand(wallet_core).await
             }
+            Self::ShowKeys { account_id } => {
+                let resolved = account_id.resolve(wallet_core.storage())?;
+                let AccountIdWithPrivacy::Private(account_id) = resolved else {
+                    anyhow::bail!(
+                        "wallet::cli::account::AccountSubcommand::ShowKeys: show-keys is only available for private accounts"
+                    );
+                };
+                let entry = wallet_core
+                    .storage()
+                    .key_chain()
+                    .private_account(account_id)
+                    .ok_or_else(|| anyhow::anyhow!("wallet::cli::account::AccountSubcommand::ShowKeys: private account not found in wallet"))?;
+                println!("{}", hex::encode(entry.key_chain.nullifier_public_key.0));
+                println!(
+                    "{}",
+                    hex::encode(entry.key_chain.viewing_public_key.to_bytes())
+                );
+                Ok(SubcommandReturnValue::Empty)
+            }
         }
     }
 }
diff --git a/wallet/src/cli/group.rs b/wallet/src/cli/group.rs
index 987f7a3a..d6621ee7 100644
--- a/wallet/src/cli/group.rs
+++ b/wallet/src/cli/group.rs
@@ -1,6 +1,9 @@
 use anyhow::{Context as _, Result};
 use clap::Subcommand;
-use key_protocol::key_management::group_key_holder::{GroupKeyHolder, SealingPublicKey};
+use key_protocol::key_management::{
+    group_key_holder::{GroupKeyHolder, SealingPublicKey},
+    secret_holders::ViewingSecretKey,
+};
 
 use crate::{
     WalletCore,
@@ -149,9 +152,15 @@ impl WalletSubcommand for GroupSubcommand {
                     anyhow::bail!("Sealing key already exists. Each wallet has one sealing key.");
                 }
 
-                let mut secret: nssa_core::encryption::Scalar = [0_u8; 32];
-                rand::RngCore::fill_bytes(&mut rand::rngs::OsRng, &mut secret);
-                let public_key = SealingPublicKey::from_scalar(secret);
+                let mut d = [0_u8; 32];
+                let mut z = [0_u8; 32];
+                rand::RngCore::fill_bytes(&mut rand::rngs::OsRng, &mut d);
+                rand::RngCore::fill_bytes(&mut rand::rngs::OsRng, &mut z);
+                let secret = ViewingSecretKey::new(d, z);
+                let ek_bytes = nssa_core::encryption::ViewingPublicKey::from_seed(&d, &z)
+                    .to_bytes()
+                    .to_vec();
+                let public_key = SealingPublicKey::from_bytes(ek_bytes);
 
                 wallet_core.set_sealing_secret_key(secret);
                 wallet_core.store_persistent_data()?;
diff --git a/wallet/src/cli/mod.rs b/wallet/src/cli/mod.rs
index 8acdfa67..50507941 100644
--- a/wallet/src/cli/mod.rs
+++ b/wallet/src/cli/mod.rs
@@ -285,6 +285,31 @@ pub fn read_password_from_stdin() -> Result<String> {
     Ok(password.trim().to_owned())
 }
 
+/// Parse a keys file exported by `wallet account show-keys`.
+///
+/// The file format is two lines:
+/// - Line 1: npk as hex (64 chars, 32 bytes).
+/// - Line 2: vpk as hex (2368 chars, 1184 bytes).
+///
+/// Returns `(npk_bytes, vpk_bytes)`.
+pub fn read_keys_file(path: &str) -> Result<(Vec<u8>, Vec<u8>)> {
+    let content = std::fs::read_to_string(path).with_context(|| {
+        format!("wallet::cli::read_keys_file: failed to read keys file: {path}")
+    })?;
+    let mut lines = content.lines().filter(|l| !l.trim().is_empty());
+    let npk_hex = lines.next().ok_or_else(|| {
+        anyhow::anyhow!("wallet::cli::read_keys_file: keys file is missing npk (line 1)")
+    })?;
+    let vpk_hex = lines.next().ok_or_else(|| {
+        anyhow::anyhow!("wallet::cli::read_keys_file: keys file is missing vpk (line 2)")
+    })?;
+    let npk = hex::decode(npk_hex.trim())
+        .context("wallet::cli::read_keys_file: npk in keys file must be valid hex")?;
+    let vpk = hex::decode(vpk_hex.trim())
+        .context("wallet::cli::read_keys_file: vpk in keys file must be valid hex")?;
+    Ok((npk, vpk))
+}
+
 pub fn read_mnemonic_from_stdin() -> Result<Mnemonic> {
     let mut phrase = String::new();
 
@@ -328,3 +353,77 @@ pub async fn execute_keys_restoration(wallet_core: &mut WalletCore, depth: u32)
 
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn read_keys_file_roundtrip() {
+        let npk = [0xab_u8; 32];
+        let vpk = [0xcd_u8; 1184];
+
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("test.keys");
+
+        // Simulate what `wallet account show-keys` writes.
+        std::fs::write(
+            &path,
+            format!("{}\n{}\n", hex::encode(npk), hex::encode(vpk)),
+        )
+        .unwrap();
+
+        let (parsed_npk, parsed_vpk) = read_keys_file(path.to_str().unwrap()).unwrap();
+
+        assert_eq!(parsed_npk, npk, "npk must round-trip through the keys file");
+        assert_eq!(
+            parsed_vpk,
+            vpk.to_vec(),
+            "vpk must round-trip through the keys file"
+        );
+    }
+
+    #[test]
+    fn read_keys_file_missing_vpk_returns_error() {
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("incomplete.keys");
+        std::fs::write(&path, format!("{}\n", hex::encode([0xab_u8; 32]))).unwrap();
+
+        let result = read_keys_file(path.to_str().unwrap());
+        assert!(result.is_err(), "missing vpk line must return an error");
+        assert!(
+            result.unwrap_err().to_string().contains("missing vpk"),
+            "error must mention missing vpk"
+        );
+    }
+
+    #[test]
+    fn read_keys_file_invalid_hex_returns_error() {
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("badhex.keys");
+        std::fs::write(&path, "not-hex\nalso-not-hex\n").unwrap();
+
+        let result = read_keys_file(path.to_str().unwrap());
+        assert!(result.is_err(), "invalid hex must return an error");
+    }
+
+    #[test]
+    fn read_keys_file_ignores_blank_lines() {
+        let npk = [0x11_u8; 32];
+        let vpk = [0x22_u8; 1184];
+
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("blanks.keys");
+
+        // Extra blank lines around the data should be tolerated.
+        std::fs::write(
+            &path,
+            format!("\n{}\n\n{}\n\n", hex::encode(npk), hex::encode(vpk)),
+        )
+        .unwrap();
+
+        let (parsed_npk, parsed_vpk) = read_keys_file(path.to_str().unwrap()).unwrap();
+        assert_eq!(parsed_npk, npk);
+        assert_eq!(parsed_vpk, vpk.to_vec());
+    }
+}
diff --git a/wallet/src/cli/programs/native_token_transfer.rs b/wallet/src/cli/programs/native_token_transfer.rs
index 87c38bef..e6e2098b 100644
--- a/wallet/src/cli/programs/native_token_transfer.rs
+++ b/wallet/src/cli/programs/native_token_transfer.rs
@@ -1,4 +1,4 @@
-use anyhow::Result;
+use anyhow::{Context as _, Result};
 use clap::Subcommand;
 use common::transaction::NSSATransaction;
 use nssa::AccountId;
@@ -34,13 +34,17 @@ pub enum AuthTransferSubcommand {
         #[arg(long)]
         to: Option<CliAccountMention>,
         /// `to_npk` - valid 32 byte hex string.
-        #[arg(long)]
+        #[arg(long, conflicts_with = "to_keys")]
         to_npk: Option<String>,
-        /// `to_vpk` - valid 33 byte hex string.
-        #[arg(long)]
+        /// `to_vpk` - valid hex-encoded ML-KEM-768 encapsulation key (1184 bytes).
+        #[arg(long, conflicts_with = "to_keys")]
         to_vpk: Option<String>,
+        /// Path to a keys file exported by `wallet account show-keys`, containing npk
+        /// and vpk on separate lines. Replaces `--to-npk` and `--to-vpk`.
+        #[arg(long, conflicts_with_all = ["to_npk", "to_vpk"])]
+        to_keys: Option<String>,
         /// Identifier for the recipient's private account (only used when sending to a foreign
-        /// private account via `--to-npk`/`--to-vpk`).
+        /// private account via `--to-npk`/`--to-vpk` or `--to-keys`).
         #[arg(long)]
         to_identifier: Option<u128>,
         /// amount - amount of balance to move.
@@ -100,9 +104,18 @@ impl WalletSubcommand for AuthTransferSubcommand {
                 to: to_account,
                 to_npk,
                 to_vpk,
+                to_keys,
                 to_identifier,
                 amount,
             } => {
+                // Resolve --to-keys into --to-npk / --to-vpk equivalents.
+                let (to_npk, to_vpk) = if let Some(path) = to_keys {
+                    let (npk_bytes, vpk_bytes) = crate::cli::read_keys_file(&path)?;
+                    (Some(hex::encode(npk_bytes)), Some(hex::encode(vpk_bytes)))
+                } else {
+                    (to_npk, to_vpk)
+                };
+
                 let from = from_account.resolve(wallet_core.storage())?;
                 let to = to_account
                     .as_ref()
@@ -258,7 +271,7 @@ pub enum NativeTokenTransferProgramSubcommandShielded {
         /// `to_npk` - valid 32 byte hex string.
         #[arg(long)]
         to_npk: String,
-        /// `to_vpk` - valid 33 byte hex string.
+        /// `to_vpk` - valid hex-encoded ML-KEM-768 encapsulation key (1184 bytes).
         #[arg(long)]
         to_vpk: String,
         /// Identifier for the recipient's private account.
@@ -298,7 +311,7 @@ pub enum NativeTokenTransferProgramSubcommandPrivate {
         /// `to_npk` - valid 32 byte hex string.
         #[arg(long)]
         to_npk: String,
-        /// `to_vpk` - valid 33 byte hex string.
+        /// `to_vpk` - valid hex-encoded ML-KEM-768 encapsulation key (1184 bytes).
         #[arg(long)]
         to_vpk: String,
         /// Identifier for the recipient's private account.
@@ -350,11 +363,11 @@ impl WalletSubcommand for NativeTokenTransferProgramSubcommandPrivate {
                 to_npk.copy_from_slice(&to_npk_res);
                 let to_npk = nssa_core::NullifierPublicKey(to_npk);
 
-                let to_vpk_res = hex::decode(to_vpk)?;
-                let mut to_vpk = [0_u8; 33];
-                to_vpk.copy_from_slice(&to_vpk_res);
+                let to_vpk_res = hex::decode(&to_vpk)
+                    .context("wallet::cli::programs::native_token_transfer: to_vpk must be a valid hex string")?;
                 let to_vpk =
-                    nssa_core::encryption::shared_key_derivation::Secp256k1Point(to_vpk.to_vec());
+                    nssa_core::encryption::MlKem768EncapsulationKey::from_bytes(to_vpk_res)
+                        .map_err(|e| anyhow::anyhow!("{e}"))?;
 
                 let (tx_hash, [secret_from, _]) = NativeTokenTransfer(wallet_core)
                     .send_private_transfer_to_outer_account(
@@ -427,11 +440,11 @@ impl WalletSubcommand for NativeTokenTransferProgramSubcommandShielded {
                 to_npk.copy_from_slice(&to_npk_res);
                 let to_npk = nssa_core::NullifierPublicKey(to_npk);
 
-                let to_vpk_res = hex::decode(to_vpk)?;
-                let mut to_vpk = [0_u8; 33];
-                to_vpk.copy_from_slice(&to_vpk_res);
+                let to_vpk_res = hex::decode(&to_vpk)
+                    .context("wallet::cli::programs::native_token_transfer: to_vpk must be a valid hex string")?;
                 let to_vpk =
-                    nssa_core::encryption::shared_key_derivation::Secp256k1Point(to_vpk.to_vec());
+                    nssa_core::encryption::MlKem768EncapsulationKey::from_bytes(to_vpk_res)
+                        .map_err(|e| anyhow::anyhow!("{e}"))?;
 
                 let (tx_hash, _) = NativeTokenTransfer(wallet_core)
                     .send_shielded_transfer_to_outer_account(
diff --git a/wallet/src/cli/programs/token.rs b/wallet/src/cli/programs/token.rs
index 61e24e68..19d19648 100644
--- a/wallet/src/cli/programs/token.rs
+++ b/wallet/src/cli/programs/token.rs
@@ -1,4 +1,4 @@
-use anyhow::Result;
+use anyhow::{Context as _, Result};
 use clap::Subcommand;
 use common::transaction::NSSATransaction;
 use nssa::AccountId;
@@ -41,13 +41,17 @@ pub enum TokenProgramAgnosticSubcommand {
         #[arg(long)]
         to: Option<CliAccountMention>,
         /// `to_npk` - valid 32 byte hex string.
-        #[arg(long)]
+        #[arg(long, conflicts_with = "to_keys")]
         to_npk: Option<String>,
-        /// `to_vpk` - valid 33 byte hex string.
-        #[arg(long)]
+        /// `to_vpk` - valid hex-encoded ML-KEM-768 encapsulation key (1184 bytes).
+        #[arg(long, conflicts_with = "to_keys")]
         to_vpk: Option<String>,
+        /// Path to a keys file exported by `wallet account show-keys`, containing npk
+        /// and vpk on separate lines. Replaces `--to-npk` and `--to-vpk`.
+        #[arg(long, conflicts_with_all = ["to_npk", "to_vpk"])]
+        to_keys: Option<String>,
         /// Identifier for the recipient's private account (only used when sending to a foreign
-        /// private account via `--to-npk`/`--to-vpk`).
+        /// private account via `--to-npk`/`--to-vpk` or `--to-keys`).
         #[arg(long)]
         to_identifier: Option<u128>,
         /// amount - amount of balance to move.
@@ -87,13 +91,17 @@ pub enum TokenProgramAgnosticSubcommand {
         #[arg(long)]
         holder: Option<CliAccountMention>,
         /// `holder_npk` - valid 32 byte hex string.
-        #[arg(long)]
+        #[arg(long, conflicts_with = "holder_keys")]
         holder_npk: Option<String>,
-        /// `to_vpk` - valid 33 byte hex string.
-        #[arg(long)]
+        /// `holder_vpk` - valid hex-encoded ML-KEM-768 encapsulation key (1184 bytes).
+        #[arg(long, conflicts_with = "holder_keys")]
         holder_vpk: Option<String>,
+        /// Path to a keys file exported by `wallet account show-keys`, containing npk
+        /// and vpk on separate lines. Replaces `--holder-npk` and `--holder-vpk`.
+        #[arg(long, conflicts_with_all = ["holder_npk", "holder_vpk"])]
+        holder_keys: Option<String>,
         /// Identifier for the holder's private account (only used when minting to a foreign
-        /// private account via `--holder-npk`/`--holder-vpk`).
+        /// private account via `--holder-npk`/`--holder-vpk` or `--holder-keys`).
         #[arg(long)]
         holder_identifier: Option<u128>,
         /// amount - amount of balance to mint.
@@ -170,9 +178,17 @@ impl WalletSubcommand for TokenProgramAgnosticSubcommand {
                 to,
                 to_npk,
                 to_vpk,
+                to_keys,
                 to_identifier,
                 amount,
             } => {
+                let (to_npk, to_vpk) = if let Some(path) = to_keys {
+                    let (npk_bytes, vpk_bytes) = crate::cli::read_keys_file(&path)?;
+                    (Some(hex::encode(npk_bytes)), Some(hex::encode(vpk_bytes)))
+                } else {
+                    (to_npk, to_vpk)
+                };
+
                 let from = from.resolve(wallet_core.storage())?;
                 let to = to
                     .map(|account_mention| account_mention.resolve(wallet_core.storage()))
@@ -309,9 +325,17 @@ impl WalletSubcommand for TokenProgramAgnosticSubcommand {
                 holder,
                 holder_npk,
                 holder_vpk,
+                holder_keys,
                 holder_identifier,
                 amount,
             } => {
+                let (holder_npk, holder_vpk) = if let Some(path) = holder_keys {
+                    let (npk_bytes, vpk_bytes) = crate::cli::read_keys_file(&path)?;
+                    (Some(hex::encode(npk_bytes)), Some(hex::encode(vpk_bytes)))
+                } else {
+                    (holder_npk, holder_vpk)
+                };
+
                 let definition = definition.resolve(wallet_core.storage())?;
                 let holder = holder
                     .map(|account_mention| account_mention.resolve(wallet_core.storage()))
@@ -475,7 +499,7 @@ pub enum TokenProgramSubcommandPrivate {
         /// `recipient_npk` - valid 32 byte hex string.
         #[arg(long)]
         recipient_npk: String,
-        /// `recipient_vpk` - valid 33 byte hex string.
+        /// `recipient_vpk` - valid hex-encoded ML-KEM-768 encapsulation key (1184 bytes).
         #[arg(long)]
         recipient_vpk: String,
         /// Identifier for the recipient's private account.
@@ -569,7 +593,7 @@ pub enum TokenProgramSubcommandShielded {
         /// `recipient_npk` - valid 32 byte hex string.
         #[arg(long)]
         recipient_npk: String,
-        /// `recipient_vpk` - valid 33 byte hex string.
+        /// `recipient_vpk` - valid hex-encoded ML-KEM-768 encapsulation key (1184 bytes).
         #[arg(long)]
         recipient_vpk: String,
         /// Identifier for the recipient's private account.
@@ -764,12 +788,12 @@ impl WalletSubcommand for TokenProgramSubcommandPrivate {
                 recipient_npk.copy_from_slice(&recipient_npk_res);
                 let recipient_npk = nssa_core::NullifierPublicKey(recipient_npk);
 
-                let recipient_vpk_res = hex::decode(recipient_vpk)?;
-                let mut recipient_vpk = [0_u8; 33];
-                recipient_vpk.copy_from_slice(&recipient_vpk_res);
-                let recipient_vpk = nssa_core::encryption::shared_key_derivation::Secp256k1Point(
-                    recipient_vpk.to_vec(),
-                );
+                let recipient_vpk_res = hex::decode(&recipient_vpk).context(
+                    "wallet::cli::programs::token: recipient_vpk must be a valid hex string",
+                )?;
+                let recipient_vpk =
+                    nssa_core::encryption::MlKem768EncapsulationKey::from_bytes(recipient_vpk_res)
+                        .map_err(|e| anyhow::anyhow!("{e}"))?;
 
                 let (tx_hash, [secret_sender, _]) = Token(wallet_core)
                     .send_transfer_transaction_private_foreign_account(
@@ -876,12 +900,12 @@ impl WalletSubcommand for TokenProgramSubcommandPrivate {
                 holder_npk.copy_from_slice(&holder_npk_res);
                 let holder_npk = nssa_core::NullifierPublicKey(holder_npk);
 
-                let holder_vpk_res = hex::decode(holder_vpk)?;
-                let mut holder_vpk = [0_u8; 33];
-                holder_vpk.copy_from_slice(&holder_vpk_res);
-                let holder_vpk = nssa_core::encryption::shared_key_derivation::Secp256k1Point(
-                    holder_vpk.to_vec(),
-                );
+                let holder_vpk_res = hex::decode(&holder_vpk).context(
+                    "wallet::cli::programs::token: holder_vpk must be a valid hex string",
+                )?;
+                let holder_vpk =
+                    nssa_core::encryption::MlKem768EncapsulationKey::from_bytes(holder_vpk_res)
+                        .map_err(|e| anyhow::anyhow!("{e}"))?;
 
                 let (tx_hash, [secret_definition, _]) = Token(wallet_core)
                     .send_mint_transaction_private_foreign_account(
@@ -1032,12 +1056,12 @@ impl WalletSubcommand for TokenProgramSubcommandShielded {
                 recipient_npk.copy_from_slice(&recipient_npk_res);
                 let recipient_npk = nssa_core::NullifierPublicKey(recipient_npk);
 
-                let recipient_vpk_res = hex::decode(recipient_vpk)?;
-                let mut recipient_vpk = [0_u8; 33];
-                recipient_vpk.copy_from_slice(&recipient_vpk_res);
-                let recipient_vpk = nssa_core::encryption::shared_key_derivation::Secp256k1Point(
-                    recipient_vpk.to_vec(),
-                );
+                let recipient_vpk_res = hex::decode(&recipient_vpk).context(
+                    "wallet::cli::programs::token: recipient_vpk must be a valid hex string",
+                )?;
+                let recipient_vpk =
+                    nssa_core::encryption::MlKem768EncapsulationKey::from_bytes(recipient_vpk_res)
+                        .map_err(|e| anyhow::anyhow!("{e}"))?;
 
                 let (tx_hash, _) = Token(wallet_core)
                     .send_transfer_transaction_shielded_foreign_account(
@@ -1163,12 +1187,12 @@ impl WalletSubcommand for TokenProgramSubcommandShielded {
                 holder_npk.copy_from_slice(&holder_npk_res);
                 let holder_npk = nssa_core::NullifierPublicKey(holder_npk);
 
-                let holder_vpk_res = hex::decode(holder_vpk)?;
-                let mut holder_vpk = [0_u8; 33];
-                holder_vpk.copy_from_slice(&holder_vpk_res);
-                let holder_vpk = nssa_core::encryption::shared_key_derivation::Secp256k1Point(
-                    holder_vpk.to_vec(),
-                );
+                let holder_vpk_res = hex::decode(&holder_vpk).context(
+                    "wallet::cli::programs::token: holder_vpk must be a valid hex string",
+                )?;
+                let holder_vpk =
+                    nssa_core::encryption::MlKem768EncapsulationKey::from_bytes(holder_vpk_res)
+                        .map_err(|e| anyhow::anyhow!("{e}"))?;
 
                 let (tx_hash, _) = Token(wallet_core)
                     .send_mint_transaction_shielded_foreign_account(
diff --git a/wallet/src/lib.rs b/wallet/src/lib.rs
index 85c43806..d0cce849 100644
--- a/wallet/src/lib.rs
+++ b/wallet/src/lib.rs
@@ -269,7 +269,10 @@ impl WalletCore {
     }
 
     /// Set the wallet's dedicated sealing secret key.
-    pub const fn set_sealing_secret_key(&mut self, key: nssa_core::encryption::Scalar) {
+    pub const fn set_sealing_secret_key(
+        &mut self,
+        key: key_protocol::key_management::secret_holders::ViewingSecretKey,
+    ) {
         self.storage.key_chain_mut().set_sealing_secret_key(key);
     }
 
@@ -725,7 +728,7 @@ impl WalletCore {
             .storage
             .key_chain()
             .private_account_key_chains()
-            .flat_map(|(_account_id, key_chain, index)| {
+            .flat_map(|(_account_id, key_chain, _index)| {
                 let view_tag = EncryptedAccountData::compute_view_tag(
                     &key_chain.nullifier_public_key,
                     &key_chain.viewing_public_key,
@@ -740,10 +743,8 @@ impl WalletCore {
                     .filter_map(move |(ciph_id, encrypted_data)| {
                         let ciphertext = &encrypted_data.ciphertext;
                         let commitment = &new_commitments[ciph_id];
-                        let shared_secret = key_chain.calculate_shared_secret_receiver(
-                            &encrypted_data.epk,
-                            index.and_then(ChainIndex::index),
-                        );
+                        let shared_secret =
+                            key_chain.calculate_shared_secret_receiver(&encrypted_data.epk)?;
 
                         nssa_core::EncryptionScheme::decrypt(
                             ciphertext,
@@ -825,7 +826,11 @@ impl WalletCore {
                     continue;
                 }
 
-                let shared_secret = SharedSecretKey::new(vsk, &encrypted_data.epk);
+                let Some(shared_secret) =
+                    SharedSecretKey::decapsulate(&encrypted_data.epk, &vsk.d, &vsk.z)
+                else {
+                    continue;
+                };
                 let commitment = &tx.message.new_commitments[ciph_id];
 
                 if let Some((_kind, new_acc)) = nssa_core::EncryptionScheme::decrypt(
diff --git a/wallet/src/storage/key_chain.rs b/wallet/src/storage/key_chain.rs
index 637884f1..18d450d8 100644
--- a/wallet/src/storage/key_chain.rs
+++ b/wallet/src/storage/key_chain.rs
@@ -6,7 +6,7 @@ use key_protocol::key_management::{
     KeyChain,
     group_key_holder::GroupKeyHolder,
     key_tree::{KeyTreePrivate, KeyTreePublic, chain_index::ChainIndex, traits::KeyTreeNode as _},
-    secret_holders::SeedHolder,
+    secret_holders::{SeedHolder, ViewingSecretKey},
 };
 use log::{debug, warn};
 use nssa::{Account, AccountId};
@@ -79,7 +79,7 @@ pub struct UserKeyChain {
     /// Dedicated sealing secret key for GMS distribution. Generated once via
     /// `wallet group new-sealing-key`. The corresponding public key is shared with
     /// group members so they can seal GMS for this wallet.
-    sealing_secret_key: Option<nssa_core::encryption::Scalar>,
+    sealing_secret_key: Option<ViewingSecretKey>,
 }
 
 impl UserKeyChain {
@@ -509,12 +509,12 @@ impl UserKeyChain {
 
     /// Returns the sealing secret key for GMS distribution, if it exists.
     #[must_use]
-    pub const fn sealing_secret_key(&self) -> Option<nssa_core::encryption::Scalar> {
-        self.sealing_secret_key
+    pub const fn sealing_secret_key(&self) -> Option<&ViewingSecretKey> {
+        self.sealing_secret_key.as_ref()
     }
 
     /// Sets the sealing secret key for GMS distribution.
-    pub const fn set_sealing_secret_key(&mut self, key: nssa_core::encryption::Scalar) {
+    pub const fn set_sealing_secret_key(&mut self, key: ViewingSecretKey) {
         self.sealing_secret_key = Some(key);
     }
 
@@ -584,7 +584,7 @@ impl UserKeyChain {
 
         KeyChainPersistentData {
             accounts,
-            sealing_secret_key: *sealing_secret_key,
+            sealing_secret_key: sealing_secret_key.clone(),
             group_key_holders: group_key_holders.clone(),
             shared_private_accounts: shared_private_accounts.clone(),
         }
diff --git a/wallet/src/storage/persistent.rs b/wallet/src/storage/persistent.rs
index 0c82ceaa..a233e644 100644
--- a/wallet/src/storage/persistent.rs
+++ b/wallet/src/storage/persistent.rs
@@ -5,6 +5,7 @@ use key_protocol::key_management::{
     key_tree::{
         chain_index::ChainIndex, keys_private::ChildKeysPrivate, keys_public::ChildKeysPublic,
     },
+    secret_holders::ViewingSecretKey,
 };
 use serde::{Deserialize, Serialize};
 use testnet_initial_state::{PrivateAccountPrivateInitialData, PublicAccountPrivateInitialData};
@@ -26,7 +27,7 @@ pub struct PersistentStorage {
 pub struct KeyChainPersistentData {
     pub accounts: Vec<PersistentAccountData>,
     #[serde(default)]
-    pub sealing_secret_key: Option<nssa_core::encryption::Scalar>,
+    pub sealing_secret_key: Option<ViewingSecretKey>,
     #[serde(default)]
     pub group_key_holders: BTreeMap<Label, GroupKeyHolder>,
     #[serde(default)]