From eeb1626a54422c35dda683f6e3deae28b2307df1 Mon Sep 17 00:00:00 2001
From: Daniel Wang <dan@taiko.xyz>
Date: Wed, 15 Jan 2025 10:15:09 +0800
Subject: [PATCH] encode proposer address in l2 header

---
 .../contracts/layer1/based/TaikoInbox.sol         | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/packages/protocol/contracts/layer1/based/TaikoInbox.sol b/packages/protocol/contracts/layer1/based/TaikoInbox.sol
index cebb75d4fc..67ee1cd880 100644
--- a/packages/protocol/contracts/layer1/based/TaikoInbox.sol
+++ b/packages/protocol/contracts/layer1/based/TaikoInbox.sol
@@ -128,7 +128,9 @@ abstract contract TaikoInbox is EssentialContract, ITaikoInbox, ITaiko, IFork {
             txListHash: calldataUsed
                 ? keccak256(_txList)
                 : _calcTxListHash(params.firstBlobIndex, params.numBlobs),
-            extraData: bytes32(uint256(config.baseFeeConfig.sharingPctg)),
+            // Ensure L2 block header has the proposer adddress so that blocks in p2p network can be
+            // verified based on the proposer address.
+            extraData: _encodeExtraData(config.baseFeeConfig.sharingPctg, params.proposer),
             coinbase: params.coinbase,
             batchId: stats2.numBatches,
             gasLimit: config.blockMaxGasLimit,
@@ -670,6 +672,17 @@ abstract contract TaikoInbox is EssentialContract, ITaikoInbox, ITaiko, IFork {
         require(_params.blocks.length <= _maxBlocksPerBatch, TooManyBlocks());
     }
 
+    function _encodeExtraData(
+        uint8 _baseFeeSharingPctg,
+        address _proposer
+    )
+        private
+        pure
+        returns (bytes32)
+    {
+        return bytes32(uint256(_baseFeeSharingPctg) << 160 | uint160(_proposer));
+    }
+
     // Memory-only structs ----------------------------------------------------------------------
 
     struct SyncBlock {