From 02428ec2520febb41f5be19fb6434d270d49586a Mon Sep 17 00:00:00 2001
From: Justin <drakefjustin@gmail.com>
Date: Sun, 10 Mar 2019 13:25:57 +0100
Subject: [PATCH 1/3] Do not check withdrawal credentials for existing
 validators

We should not invalidate blocks that contain a deposit with an inconsistent withdrawal credential as that would stall the chain.
---
 specs/core/0_beacon-chain.md | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index c88155f77..25e8085de 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -1341,10 +1341,7 @@ def process_deposit(state: BeaconState, deposit: Deposit) -> None:
         state.validator_balances.append(amount)
     else:
         # Increase balance by deposit amount
-        index = validator_pubkeys.index(pubkey)
-        assert state.validator_registry[index].withdrawal_credentials == withdrawal_credentials
-
-        state.validator_balances[index] += amount
+        state.validator_balances[validator_pubkeys.index(pubkey)] += amount
 ```
 
 ### Routines for updating validator status

From 0704297480b5706927999e4c337071a0e8d4abe4 Mon Sep 17 00:00:00 2001
From: Justin <drakefjustin@gmail.com>
Date: Mon, 11 Mar 2019 17:28:39 +0100
Subject: [PATCH 2/3] Update 0_beacon-chain.md

---
 specs/core/0_beacon-chain.md | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index 25e8085de..5d824f288 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -1303,21 +1303,6 @@ def process_deposit(state: BeaconState, deposit: Deposit) -> None:
     # create an invalid Merkle branch, it may admit an invalid deposit
     # object, and we need to be able to skip over it
     state.deposit_index += 1
-    
-    # Verify the proof of possession
-    proof_is_valid = bls_verify(
-        pubkey=deposit_input.pubkey,
-        message_hash=signed_root(deposit_input),
-        signature=deposit_input.proof_of_possession,
-        domain=get_domain(
-            state.fork,
-            get_current_epoch(state),
-            DOMAIN_DEPOSIT,
-        )
-    )
-    
-    if not proof_is_valid:
-        return
 
     validator_pubkeys = [v.pubkey for v in state.validator_registry]
     pubkey = deposit_input.pubkey
@@ -1325,6 +1310,19 @@ def process_deposit(state: BeaconState, deposit: Deposit) -> None:
     withdrawal_credentials = deposit_input.withdrawal_credentials
 
     if pubkey not in validator_pubkeys:
+        # Verify the proof of possession
+        if not bls_verify(
+            pubkey=deposit_input.pubkey,
+            message_hash=signed_root(deposit_input),
+            signature=deposit_input.proof_of_possession,
+            domain=get_domain(
+                state.fork,
+                get_current_epoch(state),
+                DOMAIN_DEPOSIT,
+            )
+        ):
+            return
+
         # Add new validator
         validator = Validator(
             pubkey=pubkey,

From 25f6647ef2a5a01a9000e658b276b609fb03479d Mon Sep 17 00:00:00 2001
From: Danny Ryan <dannyjryan@gmail.com>
Date: Tue, 12 Mar 2019 11:07:20 -0600
Subject: [PATCH 3/3] minor formatting

---
 specs/core/0_beacon-chain.md | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index a76da5ec3..b4554e0fd 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -1288,7 +1288,7 @@ def process_deposit(state: BeaconState, deposit: Deposit) -> None:
     serialized_deposit_data = serialize(deposit.deposit_data)
     # Deposits must be processed in order
     assert deposit.index == state.deposit_index
-    
+
     # Verify the Merkle branch
     merkle_branch_is_valid = verify_merkle_branch(
         leaf=hash(serialized_deposit_data),
@@ -1298,7 +1298,7 @@ def process_deposit(state: BeaconState, deposit: Deposit) -> None:
         root=state.latest_eth1_data.deposit_root,
     )
     assert merkle_branch_is_valid
-        
+
     # Increment the next deposit index we are expecting. Note that this
     # needs to be done here because while the deposit contract will never
     # create an invalid Merkle branch, it may admit an invalid deposit
@@ -1312,7 +1312,7 @@ def process_deposit(state: BeaconState, deposit: Deposit) -> None:
 
     if pubkey not in validator_pubkeys:
         # Verify the proof of possession
-        if not bls_verify(
+        proof_is_valid = bls_verify(
             pubkey=deposit_input.pubkey,
             message_hash=signed_root(deposit_input),
             signature=deposit_input.proof_of_possession,
@@ -1321,7 +1321,8 @@ def process_deposit(state: BeaconState, deposit: Deposit) -> None:
                 get_current_epoch(state),
                 DOMAIN_DEPOSIT,
             )
-        ):
+        )
+        if not proof_is_valid:
             return
 
         # Add new validator