diff --git a/src/ORMP.sol b/src/ORMP.sol
index 9fa7932..836efb1 100644
--- a/src/ORMP.sol
+++ b/src/ORMP.sol
@@ -33,7 +33,7 @@ contract ORMP is ReentrancyGuard, Channel {
     event MessageAssigned(
         bytes32 indexed msgHash, address indexed oracle, address indexed relayer, uint256 oracleFee, uint256 relayerFee
     );
-    event HashImported(address indexed oracle, bytes32 indexed lookupKey, bytes32 indexed hash);
+    event HashImported(address indexed oracle, uint256 chainId, address channel, uint256 msgIndex, bytes32 hash);
 
     /// oracle => lookupKey => hash
     mapping(address => mapping(bytes32 => bytes32)) public hashLookup;
@@ -73,11 +73,14 @@ contract ORMP is ReentrancyGuard, Channel {
     /// @dev Import hash by any oracle address.
     /// @notice Hash is an abstract of the proof system, it can be a block hash or a message root hash,
     ///  		specifically provided by oracles.
-    /// @param lookupKey The key for loop up hash.
+    /// @param chainId The source chain id.
+    /// @param channel The message channel.
+    /// @param msgIndex The source chain message index.
     /// @param hash_ The hash to import.
-    function importHash(bytes32 lookupKey, bytes32 hash_) external {
+    function importHash(uint256 chainId, address channel, uint256 msgIndex, bytes32 hash_) external {
+        bytes32 lookupKey = keccak256(abi.encode(chainId, channel, msgIndex));
         hashLookup[msg.sender][lookupKey] = hash_;
-        emit HashImported(msg.sender, lookupKey, hash_);
+        emit HashImported(msg.sender, chainId, channel, msgIndex, hash_);
     }
 
     function _handleFee(
diff --git a/src/eco/Oracle.sol b/src/eco/Oracle.sol
index e042194..92c6bc9 100644
--- a/src/eco/Oracle.sol
+++ b/src/eco/Oracle.sol
@@ -64,15 +64,11 @@ contract Oracle is Verifier {
         external
         onlyOwner
     {
-        IORMP(PROTOCOL).importHash(_lookupkey(chainId, channel, msgIndex), msgHash);
+        IORMP(PROTOCOL).importHash(chainId, channel, msgIndex, msgHash);
     }
 
     function hashOf(uint256 chainId, address channel, uint256 msgIndex) public view override returns (bytes32) {
-        return IORMP(PROTOCOL).hashLookup(address(this), _lookupkey(chainId, channel, msgIndex));
-    }
-
-    function _lookupkey(uint256 chainId, address channel, uint256 msgIndex) internal pure returns (bytes32) {
-        return keccak256(abi.encode(chainId, channel, msgIndex));
+        return IORMP(PROTOCOL).hashLookup(address(this), keccak256(abi.encode(chainId, channel, msgIndex)));
     }
 
     function changeOwner(address newOwner) external onlyOwner {
diff --git a/src/eco/Relayer.sol b/src/eco/Relayer.sol
index 56fa2a5..fa47c3c 100644
--- a/src/eco/Relayer.sol
+++ b/src/eco/Relayer.sol
@@ -115,7 +115,7 @@ contract Relayer {
         return sourceToken + payloadToken;
     }
 
-    function relay(Message calldata message, bytes calldata proof) external onlyApproved {
-        IORMP(PROTOCOL).recv(message, proof);
+    function relay(Message calldata message) external onlyApproved {
+        IORMP(PROTOCOL).recv(message, "");
     }
 }
diff --git a/src/interfaces/IORMP.sol b/src/interfaces/IORMP.sol
index 654bb91..e3a65ba 100644
--- a/src/interfaces/IORMP.sol
+++ b/src/interfaces/IORMP.sol
@@ -77,9 +77,11 @@ interface IORMP {
     /// @dev Import hash by any oracle address.
     /// @notice Hash is an abstract of the proof system, it can be a block hash or a message root hash,
     ///  		specifically provided by oracles.
-    /// @param lookupKey The key for loop up hash.
+    /// @param chainId The source chain id.
+    /// @param channel The message channel.
+    /// @param msgIndex The source chain message index.
     /// @param hash_ The hash to import.
-    function importHash(bytes32 lookupKey, bytes32 hash_) external;
+    function importHash(uint256 chainId, address channel, uint256 msgIndex, bytes32 hash_) external;
 
     /// @dev Fetch hash.
     /// @param oracle The oracle address.
diff --git a/test/eco/Relayer.t.sol b/test/eco/Relayer.t.sol
index 0cb0d0d..b132c41 100644
--- a/test/eco/Relayer.t.sol
+++ b/test/eco/Relayer.t.sol
@@ -93,7 +93,7 @@ contract RelayerTest is Test {
             gasLimit: 0,
             encoded: ""
         });
-        relayer.relay(message, "");
+        relayer.relay(message);
     }
 
     function recv(Message calldata message, bytes calldata proof) external returns (bool) {}