Introduce ExecutionAddress type

setup.py

@@ -535,7 +535,7 @@ class NoopExecutionEngine(ExecutionEngine):
                         parent_hash: Hash32,
                         timestamp: uint64,
                         random: Bytes32,
-                        feeRecipient: Bytes20) -> uint64:
+                        feeRecipient: ExecutionAddress) -> uint64:
         raise NotImplementedError("no default block production")
 
     def get_payload(self: ExecutionEngine, payload_id: uint64) -> ExecutionPayload:

specs/merge/beacon-chain.md

@@ -54,6 +54,7 @@ This patch adds transaction execution to the beacon chain as part of the Merge f
 | - | - | - |
 | `OpaqueTransaction` | `ByteList[MAX_BYTES_PER_OPAQUE_TRANSACTION]` | a [typed transaction envelope](https://eips.ethereum.org/EIPS/eip-2718#opaque-byte-array-rather-than-an-rlp-array) structured as `TransactionType \|\| TransactionPayload` |
 | `Transaction` | `Union[OpaqueTransaction]` | a transaction |
+| `ExecutionAddress` | `Bytes20` | Address of account on the execution layer |
 
 ## Constants
 
@@ -159,7 +160,7 @@ class BeaconState(Container):
 class ExecutionPayload(Container):
     # Execution block header fields
     parent_hash: Hash32
-    coinbase: Bytes20  # 'beneficiary' in the yellow paper
+    coinbase: ExecutionAddress  # 'beneficiary' in the yellow paper
     state_root: Bytes32
     receipt_root: Bytes32  # 'receipts root' in the yellow paper
     logs_bloom: ByteVector[BYTES_PER_LOGS_BLOOM]
@@ -181,7 +182,7 @@ class ExecutionPayload(Container):
 class ExecutionPayloadHeader(Container):
     # Execution block header fields
     parent_hash: Hash32
-    coinbase: Bytes20
+    coinbase: ExecutionAddress
     state_root: Bytes32
     receipt_root: Bytes32
     logs_bloom: ByteVector[BYTES_PER_LOGS_BLOOM]

specs/merge/validator.md

@@ -53,7 +53,7 @@ def prepare_payload(self: ExecutionEngine,
                     parent_hash: Hash32,
                     timestamp: uint64,
                     random: Bytes32,
-                    fee_recipient: Bytes20) -> uint64:
+                    fee_recipient: ExecutionAddress) -> uint64:
     """
     Return ``payload_id`` that is used to obtain the execution payload in a subsequent ``get_payload`` call.
     """
@@ -103,7 +103,7 @@ def get_pow_block_at_total_difficulty(total_difficulty: uint256, pow_chain: Sequ
 
 def prepare_execution_payload(state: BeaconState,
                               pow_chain: Sequence[PowBlock],
-                              fee_recipient: Bytes20,
+                              fee_recipient: ExecutionAddress,
                               execution_engine: ExecutionEngine) -> Optional[uint64]:
     if not is_merge_complete(state):
         terminal_pow_block = get_pow_block_at_total_difficulty(TERMINAL_TOTAL_DIFFICULTY, pow_chain)

tests/core/pyspec/eth2spec/test/helpers/execution_payload.py

@@ -11,7 +11,7 @@ def build_empty_execution_payload(spec, state, randao_mix=None):
 
     payload = spec.ExecutionPayload(
         parent_hash=latest.block_hash,
-        coinbase=spec.Bytes20(),
+        coinbase=spec.ExecutionAddress(),
         state_root=latest.state_root,  # no changes to the state
         receipt_root=b"no receipts here" + b"\x00" * 16,  # TODO: root of empty MPT may be better.
         logs_bloom=spec.ByteVector[spec.BYTES_PER_LOGS_BLOOM](),  # TODO: zeroed logs bloom for empty logs ok?