diff --git a/config/contracts.json b/config/contracts.json
index 0f85e33..7491c92 100644
--- a/config/contracts.json
+++ b/config/contracts.json
@@ -34,7 +34,11 @@
       "Owned": {"deploy": false},
       "IdentityGasRelay": {"gasLimit": 4000000},
       "IdentityKernel": {"deploy": false},
-      "IdentityFactory": {"args":["0x00"], "gasLimit": 4000000},
+      "IdentityFactory": {
+        "args":["0x00"], 
+        "gasLimit": 5000000,
+        "onDeploy": ["IdentityFactory.methods.setKernel('$IdentityGasRelay').send({gasLimit: 1000000})"]
+      },
       "SNTController": {"deploy": false},
       "UpdatedIdentityKernel": {"deploy": false},
       "TestContract": {"deploy": false}
diff --git a/contracts/deploy/Factory.sol b/contracts/deploy/Factory.sol
index b85a80e..eec1b73 100644
--- a/contracts/deploy/Factory.sol
+++ b/contracts/deploy/Factory.sol
@@ -13,7 +13,8 @@ contract Factory is Controlled {
         bytes32 codeHash;
     }
 
-    mapping (address => uint256) versionMap;
+    mapping(bytes32 => uint256) hashToVersion;
+    mapping(address => uint256) versionMap;
 
     Version[] versionLog;
     uint256 latestUpdate;
@@ -50,6 +51,10 @@ contract Factory is Controlled {
         );
     }
 
+    function isKernel(bytes32 _codeHash) public returns (bool){
+        return hashToVersion[_codeHash] > 0;
+    }
+
     function isKernel(address _addr) public returns (bool){
         return versionMap[_addr] > 0;
     }
@@ -86,6 +91,7 @@ contract Factory is Controlled {
         require(_kernel != latestKernel);
         bytes32 _codeHash = getCodeHash(_kernel);
         versionMap[_kernel] = versionLog.length;
+        hashToVersion[_codeHash] = versionLog.length;
         versionLog.push(Version({blockNumber: block.number, timestamp: block.timestamp, kernel: _kernel, codeHash: _codeHash}));
         latestUpdate = block.timestamp;
         latestKernel = _kernel;
diff --git a/gas-relayer/config/config.json b/gas-relayer/config/config.json
index b2893ac..7caf8a3 100644
--- a/gas-relayer/config/config.json
+++ b/gas-relayer/config/config.json
@@ -25,7 +25,7 @@
             "name": "Ethereum",
             "symbol": "ETH"
         },
-        "0xf8a85AfA502a0A27aAA3528C62eB059Db97a6007": {
+        "0xD10e6dAe987Dcc0B3ADaA375C9f59690a4C97a27": {
             "minRelayFactor": 10000,
             "name": "Random Test Token",
             "symbol": "RDN",
@@ -37,8 +37,8 @@
         "IdentityGasRelay": {
             "abiFile": "../abi/IdentityGasRelay.json",
             "isIdentity": true,
-            "factoryAddress": "0xdd8b8aCf484875dC6565F6B614B8Dc9C7f074C00",
-            "kernelVerification": "isKernel(address _addr)",
+            "factoryAddress": "0x5F6cDe612C45039AaC867075703Bc118cEA4D531",
+            "kernelVerification": "isKernel(bytes32)",
             "allowedFunctions": [
                 { 
                     "function": "approveAndCallGasRelayed(address,address,uint256,bytes,uint256,uint256,uint256,address,bytes)", 
diff --git a/gas-relayer/src/contract-settings.js b/gas-relayer/src/contract-settings.js
index ba617a0..16a4a8c 100644
--- a/gas-relayer/src/contract-settings.js
+++ b/gas-relayer/src/contract-settings.js
@@ -1,5 +1,3 @@
-const md5 = require('md5');
-
 class ContractSettings {
 
     constructor(config, web3, eventEmitter){
@@ -45,7 +43,7 @@ class ContractSettings {
         this.pendingToLoad++;
         this.web3.eth.getCode(this.contracts[topicName].address)
         .then(code => {
-            this.contracts[topicName].code = md5(code);
+            this.contracts[topicName].code = this.web3.utils.soliditySha3(code);
             this.pendingToLoad--;
             if(this.pendingToLoad == 0) this.events.emit("setup:complete", this);
             })
diff --git a/gas-relayer/src/message-processor.js b/gas-relayer/src/message-processor.js
index 2682504..01fe2d1 100644
--- a/gas-relayer/src/message-processor.js
+++ b/gas-relayer/src/message-processor.js
@@ -46,7 +46,7 @@ class MessageProcessor {
             
         // Get code from address and compare it against the contract code
         if(!contract.isIdentity){
-            const code = md5(await this.web3.eth.getCode(input.address));
+            const code = this.web3.utils.soliditySha3(await this.web3.eth.getCode(input.address));
             if(code != contract.code){
                 this._reply('Invalid contract code', message);
                 return false;
@@ -57,11 +57,14 @@ class MessageProcessor {
 
     async _validateInstance(message, input){
         const contract = this.settings.getContractByTopic(message.topic);
-        const kernelVerifSignature = this.web3.utils.sha3(contract.kernelVerification).slice(0, 10);
-        
-        return await this.web3.eth.call({
+        const instanceCodeHash = this.web3.utils.soliditySha3(await this.web3.eth.getCode(input.address));
+        const kernelVerifSignature = this.web3.utils.soliditySha3(contract.kernelVerification).slice(0, 10);
+    
+        let verificationResult = await this.web3.eth.call({
             to: contract.factoryAddress, 
-            data: kernelVerifSignature + "000000000000000000000000" + input.address.slice(2)});
+            data: kernelVerifSignature + instanceCodeHash.slice(2)});
+
+        return web3.eth.abi.decodeParameter('bool', verificationResult);;
     }
 
     _extractInput(message){