diff --git a/nssa/Cargo.toml b/nssa/Cargo.toml
index 5788e30..7e1a1ad 100644
--- a/nssa/Cargo.toml
+++ b/nssa/Cargo.toml
@@ -14,3 +14,4 @@ secp256k1 = "0.31.1"
 
 [dev-dependencies]
 test-program-methods = { path = "test_program_methods" }
+hex = "0.4.3"
diff --git a/nssa/src/public_transaction/encoding.rs b/nssa/src/public_transaction/encoding.rs
index 01483a5..eb7fbfc 100644
--- a/nssa/src/public_transaction/encoding.rs
+++ b/nssa/src/public_transaction/encoding.rs
@@ -11,9 +11,9 @@ const MESSAGE_ENCODING_PREFIX: &[u8; MESSAGE_ENCODING_PREFIX_LEN] = b"NSSA/v0.1/
 
 impl Message {
     /// Serializes a `Message` into bytes in the following layout:
-    /// TAG || <program_id>  (bytes LE) * 8 || addresses_len (4 bytes LE) || addresses (32 bytes * N) || nonces_len (4 bytes LE) || nonces (16 bytes * M) || instruction_data_len || instruction_data (4 bytes * K)
+    /// PREFIX || <program_id>  (4 bytes LE) * 8 || addresses_len (4 bytes LE) || addresses (32 bytes * N) || nonces_len (4 bytes LE) || nonces (16 bytes LE * M) || instruction_data_len || instruction_data (4 bytes LE * K)
     /// Integers and words are encoded in little-endian byte order, and fields appear in the above order.
-    pub(crate) fn message_to_bytes(&self) -> Vec<u8> {
+    pub(crate) fn to_bytes(&self) -> Vec<u8> {
         let mut bytes = MESSAGE_ENCODING_PREFIX.to_vec();
         // program_id: [u32; 8]
         for word in &self.program_id {
@@ -27,6 +27,7 @@ impl Message {
             bytes.extend_from_slice(addr.value());
         }
         // nonces: Vec<u128>
+        // serialize length as u32 little endian, then all nonces concatenated in LE
         let nonces_len = self.nonces.len() as u32;
         bytes.extend(&nonces_len.to_le_bytes());
         for nonce in &self.nonces {
@@ -93,8 +94,8 @@ impl WitnessSet {
         let size = self.signatures_and_public_keys.len() as u32;
         bytes.extend_from_slice(&size.to_le_bytes());
         for (signature, public_key) in &self.signatures_and_public_keys {
-            bytes.extend_from_slice(&signature.value);
-            bytes.extend_from_slice(&public_key.0);
+            bytes.extend_from_slice(signature.to_bytes());
+            bytes.extend_from_slice(public_key.to_bytes());
         }
         bytes
     }
@@ -120,7 +121,7 @@ impl WitnessSet {
 
 impl PublicTransaction {
     pub fn to_bytes(&self) -> Vec<u8> {
-        let mut bytes = self.message.message_to_bytes();
+        let mut bytes = self.message.to_bytes();
         bytes.extend_from_slice(&self.witness_set.to_bytes());
         bytes
     }
diff --git a/nssa/src/public_transaction/witness_set.rs b/nssa/src/public_transaction/witness_set.rs
index 7d8b5bc..83edf66 100644
--- a/nssa/src/public_transaction/witness_set.rs
+++ b/nssa/src/public_transaction/witness_set.rs
@@ -11,7 +11,7 @@ pub struct WitnessSet {
 
 impl WitnessSet {
     pub fn for_message(message: &Message, private_keys: &[&PrivateKey]) -> Self {
-        let message_bytes = message.message_to_bytes();
+        let message_bytes = message.to_bytes();
         let signatures_and_public_keys = private_keys
             .iter()
             .map(|&key| (Signature::new(key, &message_bytes), PublicKey::new(key)))
@@ -22,7 +22,7 @@ impl WitnessSet {
     }
 
     pub fn is_valid_for(&self, message: &Message) -> bool {
-        let message_bytes = message.message_to_bytes();
+        let message_bytes = message.to_bytes();
         for (signature, public_key) in self.iter_signatures() {
             if !signature.is_valid_for(&message_bytes, &public_key) {
                 return false;
diff --git a/nssa/src/signature/encoding.rs b/nssa/src/signature/encoding.rs
index 005cea9..a7f112e 100644
--- a/nssa/src/signature/encoding.rs
+++ b/nssa/src/signature/encoding.rs
@@ -10,6 +10,10 @@ impl PublicKey {
         cursor.read_exact(&mut value).unwrap();
         Self(value)
     }
+
+    pub(crate) fn to_bytes(&self) -> &[u8] {
+        &self.0
+    }
 }
 
 impl Signature {
@@ -19,4 +23,8 @@ impl Signature {
         cursor.read_exact(&mut value).unwrap();
         Self { value }
     }
+
+    pub(crate) fn to_bytes(&self) -> &[u8] {
+        &self.value
+    }
 }
diff --git a/nssa/src/signature/public_key.rs b/nssa/src/signature/public_key.rs
index f7a8c25..830f6b1 100644
--- a/nssa/src/signature/public_key.rs
+++ b/nssa/src/signature/public_key.rs
@@ -21,3 +21,47 @@ impl PublicKey {
     }
 }
 
+#[cfg(test)]
+mod tests {
+    use crate::{PrivateKey, PublicKey};
+    fn hex_to_32_bytes(hex: &str) -> [u8; 32] {
+        hex::decode(hex).unwrap().try_into().unwrap()
+    }
+
+    /// Test vectors from
+    /// https://github.com/bitcoin/bips/blob/master/bip-0340/test-vectors.csv
+    const BIP340_PK_TEST_VECTORS: [(&str, &str); 5] = [
+        (
+            "0000000000000000000000000000000000000000000000000000000000000003",
+            "F9308A019258C31049344F85F89D5229B531C845836F99B08601F113BCE036F9",
+        ),
+        (
+            "B7E151628AED2A6ABF7158809CF4F3C762E7160F38B4DA56A784D9045190CFEF",
+            "DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659",
+        ),
+        (
+            "C90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B14E5C9",
+            "DD308AFEC5777E13121FA72B9CC1B7CC0139715309B086C960E18FD969774EB8",
+        ),
+        (
+            "0B432B2677937381AEF05BB02A66ECD012773062CF3FA2549E44F58ED2401710",
+            "25D1DFF95105F5253C4022F628A996AD3A0D95FBF21D468A1B33F8C160D8F517",
+        ),
+        (
+            "0340034003400340034003400340034003400340034003400340034003400340",
+            "778CAA53B4393AC467774D09497A87224BF9FAB6F6E68B23086497324D6FD117",
+        ),
+    ];
+
+    #[test]
+    fn test_bip340_pk_test_vectors() {
+        for (i, (private_key_hex, expected_public_key_hex)) in
+            BIP340_PK_TEST_VECTORS.iter().enumerate()
+        {
+            let key = PrivateKey::try_new(hex_to_32_bytes(private_key_hex)).unwrap();
+            let public_key = PublicKey::new(&key);
+            let expected_public_key = PublicKey(hex_to_32_bytes(expected_public_key_hex));
+            assert_eq!(public_key, expected_public_key, "Failed test vector at index {i}");
+        }
+    }
+}