diff --git a/packages/fuel/out/release/fuel-abi.json b/packages/fuel/out/release/fuel-abi.json
index cd35ca6..326d709 100644
--- a/packages/fuel/out/release/fuel-abi.json
+++ b/packages/fuel/out/release/fuel-abi.json
@@ -14,7 +14,7 @@
     {
       "type": "enum std::option::Option<struct HTLC>",
       "concreteTypeId": "2b4a62e8055c70f8b1030ea7e332c3ba1288d018326932966c12e739e3b39747",
-      "metadataTypeId": 2,
+      "metadataTypeId": 3,
       "typeArguments": [
         "86d8c6f7cae21a575a05f79ba638fb0dad5282a73d2f4ff843b273d20db407a9"
       ]
@@ -30,42 +30,47 @@
     {
       "type": "struct HTLC",
       "concreteTypeId": "86d8c6f7cae21a575a05f79ba638fb0dad5282a73d2f4ff843b273d20db407a9",
-      "metadataTypeId": 5
+      "metadataTypeId": 6
     },
     {
       "type": "struct TokenCommitted",
       "concreteTypeId": "78acd35e37502d98e65a2ab559087dd216a287a7451d4f935b390221d298b700",
-      "metadataTypeId": 6
+      "metadataTypeId": 7
     },
     {
       "type": "struct TokenLockAdded",
       "concreteTypeId": "ae438802fd396d1a9e35c5d90ac591a3b07fefce2c695bbe8b413c97a45580a0",
-      "metadataTypeId": 7
+      "metadataTypeId": 8
     },
     {
       "type": "struct TokenLocked",
       "concreteTypeId": "40a5216fe49383a63f3bc1fc9ed173b15d65507cf0afb1bf60b45455cf3c8cc2",
-      "metadataTypeId": 8
+      "metadataTypeId": 9
     },
     {
       "type": "struct TokenRedeemed",
       "concreteTypeId": "763c4ffa6ea9a443fa0bd80203751132ca64f37f23d2a7637091737e9cd5b7d7",
-      "metadataTypeId": 9
+      "metadataTypeId": 10
     },
     {
       "type": "struct TokenRefuned",
       "concreteTypeId": "3305d3421a33ef2ee99d7b6a3d1e24e0f49eaee9476c84a9066d33eb7dc306d7",
-      "metadataTypeId": 10
+      "metadataTypeId": 11
     },
     {
       "type": "struct std::address::Address",
       "concreteTypeId": "f597b637c3b0f588fb8d7086c6f4735caa3122b85f0423b82e489f9bb58e2308",
-      "metadataTypeId": 11
+      "metadataTypeId": 12
+    },
+    {
+      "type": "struct std::b512::B512",
+      "concreteTypeId": "745e252e80bec590efc3999ae943f07ccea4d5b45b00bb6575499b64abdd3322",
+      "metadataTypeId": 14
     },
     {
       "type": "struct std::vec::Vec<u256>",
       "concreteTypeId": "742d7b76206a39cfad7eaec9b457390bbd0a92fe1da596db414daa0e4964bf82",
-      "metadataTypeId": 15,
+      "metadataTypeId": 17,
       "typeArguments": [
         "1b5759d94094368cfd443019e7ca5ec4074300e544e5ea993a979f5da627261e"
       ]
@@ -85,22 +90,32 @@
       "metadataTypeId": 0
     },
     {
-      "type": "enum std::identity::Identity",
+      "type": "[_; 2]",
       "metadataTypeId": 1,
+      "components": [
+        {
+          "name": "__array_element",
+          "typeId": "7c5ee1cecf5f8eacd1284feb5f0bf2bdea533a51e2f0c9aabe9236d335989f3b"
+        }
+      ]
+    },
+    {
+      "type": "enum std::identity::Identity",
+      "metadataTypeId": 2,
       "components": [
         {
           "name": "Address",
-          "typeId": 11
+          "typeId": 12
         },
         {
           "name": "ContractId",
-          "typeId": 13
+          "typeId": 15
         }
       ]
     },
     {
       "type": "enum std::option::Option",
-      "metadataTypeId": 2,
+      "metadataTypeId": 3,
       "components": [
         {
           "name": "None",
@@ -108,24 +123,24 @@
         },
         {
           "name": "Some",
-          "typeId": 3
+          "typeId": 4
         }
       ],
       "typeParameters": [
-        3
+        4
       ]
     },
     {
       "type": "generic T",
-      "metadataTypeId": 3
+      "metadataTypeId": 4
     },
     {
       "type": "raw untyped ptr",
-      "metadataTypeId": 4
+      "metadataTypeId": 5
     },
     {
       "type": "struct HTLC",
-      "metadataTypeId": 5,
+      "metadataTypeId": 6,
       "components": [
         {
           "name": "dstAddress",
@@ -145,11 +160,11 @@
         },
         {
           "name": "sender",
-          "typeId": 11
+          "typeId": 12
         },
         {
           "name": "srcReceiver",
-          "typeId": 11
+          "typeId": 12
         },
         {
           "name": "hashlock",
@@ -169,7 +184,7 @@
         },
         {
           "name": "assetId",
-          "typeId": 12
+          "typeId": 13
         },
         {
           "name": "redeemed",
@@ -183,7 +198,7 @@
     },
     {
       "type": "struct TokenCommitted",
-      "metadataTypeId": 6,
+      "metadataTypeId": 7,
       "components": [
         {
           "name": "Id",
@@ -203,11 +218,11 @@
         },
         {
           "name": "sender",
-          "typeId": 11
+          "typeId": 12
         },
         {
           "name": "srcReceiver",
-          "typeId": 11
+          "typeId": 12
         },
         {
           "name": "srcAsset",
@@ -223,13 +238,13 @@
         },
         {
           "name": "assetId",
-          "typeId": 12
+          "typeId": 13
         }
       ]
     },
     {
       "type": "struct TokenLockAdded",
-      "metadataTypeId": 7,
+      "metadataTypeId": 8,
       "components": [
         {
           "name": "Id",
@@ -247,7 +262,7 @@
     },
     {
       "type": "struct TokenLocked",
-      "metadataTypeId": 8,
+      "metadataTypeId": 9,
       "components": [
         {
           "name": "Id",
@@ -271,11 +286,11 @@
         },
         {
           "name": "sender",
-          "typeId": 11
+          "typeId": 12
         },
         {
           "name": "srcReceiver",
-          "typeId": 11
+          "typeId": 12
         },
         {
           "name": "srcAsset",
@@ -291,13 +306,13 @@
         },
         {
           "name": "assetId",
-          "typeId": 12
+          "typeId": 13
         }
       ]
     },
     {
       "type": "struct TokenRedeemed",
-      "metadataTypeId": 9,
+      "metadataTypeId": 10,
       "components": [
         {
           "name": "Id",
@@ -305,13 +320,13 @@
         },
         {
           "name": "redeemAddress",
-          "typeId": 1
+          "typeId": 2
         }
       ]
     },
     {
       "type": "struct TokenRefuned",
-      "metadataTypeId": 10,
+      "metadataTypeId": 11,
       "components": [
         {
           "name": "Id",
@@ -321,7 +336,7 @@
     },
     {
       "type": "struct std::address::Address",
-      "metadataTypeId": 11,
+      "metadataTypeId": 12,
       "components": [
         {
           "name": "bits",
@@ -331,7 +346,7 @@
     },
     {
       "type": "struct std::asset_id::AssetId",
-      "metadataTypeId": 12,
+      "metadataTypeId": 13,
       "components": [
         {
           "name": "bits",
@@ -339,9 +354,19 @@
         }
       ]
     },
+    {
+      "type": "struct std::b512::B512",
+      "metadataTypeId": 14,
+      "components": [
+        {
+          "name": "bits",
+          "typeId": 1
+        }
+      ]
+    },
     {
       "type": "struct std::contract_id::ContractId",
-      "metadataTypeId": 13,
+      "metadataTypeId": 15,
       "components": [
         {
           "name": "bits",
@@ -351,11 +376,11 @@
     },
     {
       "type": "struct std::vec::RawVec",
-      "metadataTypeId": 14,
+      "metadataTypeId": 16,
       "components": [
         {
           "name": "ptr",
-          "typeId": 4
+          "typeId": 5
         },
         {
           "name": "cap",
@@ -363,20 +388,20 @@
         }
       ],
       "typeParameters": [
-        3
+        4
       ]
     },
     {
       "type": "struct std::vec::Vec",
-      "metadataTypeId": 15,
+      "metadataTypeId": 17,
       "components": [
         {
           "name": "buf",
-          "typeId": 14,
+          "typeId": 16,
           "typeArguments": [
             {
               "name": "",
-              "typeId": 3
+              "typeId": 4
             }
           ]
         },
@@ -386,7 +411,7 @@
         }
       ],
       "typeParameters": [
-        3
+        4
       ]
     }
   ],
@@ -418,6 +443,37 @@
         }
       ]
     },
+    {
+      "inputs": [
+        {
+          "name": "signature",
+          "concreteTypeId": "745e252e80bec590efc3999ae943f07ccea4d5b45b00bb6575499b64abdd3322"
+        },
+        {
+          "name": "Id",
+          "concreteTypeId": "1b5759d94094368cfd443019e7ca5ec4074300e544e5ea993a979f5da627261e"
+        },
+        {
+          "name": "hashlock",
+          "concreteTypeId": "7c5ee1cecf5f8eacd1284feb5f0bf2bdea533a51e2f0c9aabe9236d335989f3b"
+        },
+        {
+          "name": "timelock",
+          "concreteTypeId": "1506e6f44c1d6291cdf46395a8e573276a4fa79e8ace3fc891e092ef32d1b0a0"
+        }
+      ],
+      "name": "add_lock_sig",
+      "output": "1b5759d94094368cfd443019e7ca5ec4074300e544e5ea993a979f5da627261e",
+      "attributes": [
+        {
+          "name": "storage",
+          "arguments": [
+            "read",
+            "write"
+          ]
+        }
+      ]
+    },
     {
       "inputs": [
         {
diff --git a/packages/fuel/out/release/fuel.bin b/packages/fuel/out/release/fuel.bin
index 419751a..5add5f9 100644
Binary files a/packages/fuel/out/release/fuel.bin and b/packages/fuel/out/release/fuel.bin differ
diff --git a/packages/fuel/scripts/addLock.ts b/packages/fuel/scripts/addLock.ts
index ee2294e..cc8b84b 100644
--- a/packages/fuel/scripts/addLock.ts
+++ b/packages/fuel/scripts/addLock.ts
@@ -5,18 +5,19 @@ import * as path from 'path';
 const filePath = path.join(__dirname, '../out/release/fuel-abi.json');
 const contractAbi = JSON.parse(fs.readFileSync(filePath, 'utf-8'));
 
-const contractAddressString = '0x33dab65c45258fea05215fca2a2578fb94b13920d5a736e02ac9aae517b2bd96';
+const contractAddressString = '0x00f3dfc843089523a41a08a611ad39eef57de6ebdb58915840ed81d3fe9a5476';
 
 async function getWalletBalances() {
   const provider = await Provider.create('https://testnet.fuel.network/v1/graphql');
   const mnemonic = 'energy knife treat involve affair tobacco school verb risk laugh exchange vendor';
+  // const mnemonic = 'connect people age absurd suggest river trust lunch joke clerk clinic blind';
   const wallet: WalletUnlocked = Wallet.fromMnemonic(mnemonic);
   wallet.connect(provider);
 
   const contractAddress = Address.fromB256(contractAddressString);
   const contractInstance = new Contract(contractAddress, contractAbi, wallet);
-  const Id = 1n;
-  const hashlock = "0xd4a671c0bb24f780c8ed7c13cfb6a554585bea038416afdcf806e73381db8417";
+  const Id = 54079385413661825002756453772014361870896886140818619726462513491823303364787n;
+  const hashlock = "0x3b7674662e6569056cef73dab8b7809085a32beda0e8eb9e9b580cfc2af22a55";
   const currentUnixTime = Math.floor(Date.now() / 1000) + 3600;
   const timelock = DateTime.fromUnixSeconds(currentUnixTime).toTai64();           
 
diff --git a/packages/fuel/scripts/addLockSig.ts b/packages/fuel/scripts/addLockSig.ts
new file mode 100644
index 0000000..42506b9
--- /dev/null
+++ b/packages/fuel/scripts/addLockSig.ts
@@ -0,0 +1,56 @@
+import { Contract, Wallet, Provider, Address, DateTime, WalletUnlocked, Signer, sha256, bn, hashMessage, keccak256, arrayify, hexlify, BytesLike } from 'fuels';
+import * as fs from 'fs';
+import * as path from 'path';
+
+const filePath = path.join(__dirname, '../out/release/fuel-abi.json');
+const contractAbi = JSON.parse(fs.readFileSync(filePath, 'utf-8'));
+
+const contractAddressString = '0x00f3dfc843089523a41a08a611ad39eef57de6ebdb58915840ed81d3fe9a5476';
+
+async function getWalletBalances() {
+  const provider = await Provider.create('https://testnet.fuel.network/v1/graphql');
+  const signerMnemonic = 'energy knife treat involve affair tobacco school verb risk laugh exchange vendor';
+  const signerWallet: WalletUnlocked = Wallet.fromMnemonic(signerMnemonic);
+  signerWallet.connect(provider);
+  
+  const senderMnemonic = 'connect people age absurd suggest river trust lunch joke clerk clinic blind';
+  const senderWallet: WalletUnlocked = Wallet.fromMnemonic(senderMnemonic);
+  senderWallet.connect(provider);
+
+  const contractAddress = Address.fromB256(contractAddressString);
+  const contractInstance = new Contract(contractAddress, contractAbi, senderWallet);
+  const Id = 54079385413661825002756453772014361870896886140818619726462513491823303364788n;
+  const hashlock = "0x3b7674662e6569056cef73dab8b7809085a32beda0e8eb9e9b580cfc2af22a55";
+  const currentUnixTime = Math.floor(Date.now() / 1000) + 3600;
+  const timelock = DateTime.fromUnixSeconds(currentUnixTime).toTai64();
+
+  const IdHex = '0x' + Id.toString(16).padStart(64, '0');
+  const timelockHex = '0x' + BigInt(timelock).toString(16).padStart(64, '0');
+
+  const msg = [IdHex,hashlock,timelockHex];
+
+  const msgBytes = Uint8Array.from(
+  msg.flatMap(hexStr => Array.from(arrayify(hexStr)))
+);
+  let signedmessage = signerWallet.signer().sign(sha256(msgBytes))
+  const signature  = hexlify(signedmessage) 
+  console.log('signiature verifeid off chain: ',signerWallet.address.toB256() == Signer.recoverAddress(sha256(msgBytes),signature).toB256());
+
+  try {
+    const { transactionId, waitForResult } = await contractInstance.functions
+      .add_lock_sig(signature,IdHex,hashlock,timelock)
+      .call();
+
+    const { logs,value } = await waitForResult();
+
+    console.log('tx id: ', transactionId);
+    console.log('add_lock function logs: ',logs[0]);
+    console.log('add_lock function result:', value);
+  } catch (error) {
+    console.error('Error calling add_lock function:', error);
+  }
+}
+
+getWalletBalances().catch(console.error);
+
+
diff --git a/packages/fuel/scripts/commit.ts b/packages/fuel/scripts/commit.ts
index 2002a8c..ea92e3c 100644
--- a/packages/fuel/scripts/commit.ts
+++ b/packages/fuel/scripts/commit.ts
@@ -5,7 +5,7 @@ import * as path from 'path';
 const filePath = path.join(__dirname, '../out/release/fuel-abi.json');
 const contractAbi = JSON.parse(fs.readFileSync(filePath, 'utf-8'));
 
-const contractAddressString = '0x33dab65c45258fea05215fca2a2578fb94b13920d5a736e02ac9aae517b2bd96';
+const contractAddressString = '0x00f3dfc843089523a41a08a611ad39eef57de6ebdb58915840ed81d3fe9a5476';
 
 async function getWalletBalances() {
   const provider = await Provider.create('https://testnet.fuel.network/v1/graphql');
@@ -20,7 +20,7 @@ async function getWalletBalances() {
   const dstAddress = "0QAS8JNB0G4zVkdxABCLVG-Vy3KXE3W3zz1yxpnfu4J-B40y".padEnd(64, ' ');
   const srcAsset = "ETH".padEnd(64, ' ');
   const srcReceiver = {"bits":"0x6364b23e8c34d46d0b68d20e0c1463230a9243a1dd710a7dd8b32dfb927af53a"};
-  const currentUnixTime = Math.floor(Date.now() / 1000) + 3600;
+  const currentUnixTime = Math.floor(Date.now() / 1000) + 10;
   const timelock = DateTime.fromUnixSeconds(currentUnixTime).toTai64();           
 
   const contractAddress = Address.fromB256(contractAddressString);
diff --git a/packages/fuel/scripts/getContracts.ts b/packages/fuel/scripts/getContracts.ts
index 159b04b..8da0f0b 100644
--- a/packages/fuel/scripts/getContracts.ts
+++ b/packages/fuel/scripts/getContracts.ts
@@ -5,7 +5,7 @@ import * as path from 'path';
 const filePath = path.join(__dirname, '../out/release/fuel-abi.json');
 const contractAbi = JSON.parse(fs.readFileSync(filePath, 'utf-8'));
 
-const contractAddressString = '0xed0b3a20a5a0f6e0f6fec1a9f27630fde03fba04cb304c575543946eaf3d8756';
+const contractAddressString = '0x00f3dfc843089523a41a08a611ad39eef57de6ebdb58915840ed81d3fe9a5476';
 
 async function getWalletBalances() {
   const provider = await Provider.create('https://testnet.fuel.network/v1/graphql');
diff --git a/packages/fuel/scripts/getDetails.ts b/packages/fuel/scripts/getDetails.ts
index 9834191..3c8a551 100644
--- a/packages/fuel/scripts/getDetails.ts
+++ b/packages/fuel/scripts/getDetails.ts
@@ -5,7 +5,7 @@ import * as path from 'path';
 const filePath = path.join(__dirname, '../out/release/fuel-abi.json');
 const contractAbi = JSON.parse(fs.readFileSync(filePath, 'utf-8'));
 
-const contractAddressString = '0x33dab65c45258fea05215fca2a2578fb94b13920d5a736e02ac9aae517b2bd96';
+const contractAddressString = '0x00f3dfc843089523a41a08a611ad39eef57de6ebdb58915840ed81d3fe9a5476';
 
 async function getWalletBalances() {
   const provider = await Provider.create('https://testnet.fuel.network/v1/graphql');
@@ -18,7 +18,7 @@ async function getWalletBalances() {
 
   try {
     const { transactionId, waitForResult } = await contractInstance.functions
-      .get_details(100n)
+      .get_details(101n)
       .call();
 
     const { value } = await waitForResult();
diff --git a/packages/fuel/scripts/init.ts b/packages/fuel/scripts/init.ts
index 07b2951..0908eed 100644
--- a/packages/fuel/scripts/init.ts
+++ b/packages/fuel/scripts/init.ts
@@ -5,7 +5,7 @@ import * as path from 'path';
 const filePath = path.join(__dirname, '../out/release/fuel-abi.json');
 const contractAbi = JSON.parse(fs.readFileSync(filePath, 'utf-8'));
 
-const contractAddressString = '0x33dab65c45258fea05215fca2a2578fb94b13920d5a736e02ac9aae517b2bd96';
+const contractAddressString = '0x00f3dfc843089523a41a08a611ad39eef57de6ebdb58915840ed81d3fe9a5476';
 
 async function getWalletBalances() {
   const provider = await Provider.create('https://testnet.fuel.network/v1/graphql');
diff --git a/packages/fuel/scripts/lock.ts b/packages/fuel/scripts/lock.ts
index c81377f..c6ab269 100644
--- a/packages/fuel/scripts/lock.ts
+++ b/packages/fuel/scripts/lock.ts
@@ -5,7 +5,7 @@ import * as path from 'path';
 const filePath = path.join(__dirname, '../out/release/fuel-abi.json');
 const contractAbi = JSON.parse(fs.readFileSync(filePath, 'utf-8'));
 
-const contractAddressString = '0x33dab65c45258fea05215fca2a2578fb94b13920d5a736e02ac9aae517b2bd96';
+const contractAddressString = '0x00f3dfc843089523a41a08a611ad39eef57de6ebdb58915840ed81d3fe9a5476';
 
 async function getWalletBalances() {
   const provider = await Provider.create('https://testnet.fuel.network/v1/graphql');
@@ -15,15 +15,15 @@ async function getWalletBalances() {
 
 // NOTE: All string variables should be padded to ensure they have 64 characters,
 // as the contract accepts only the str[64] type for string inputs.
-  const Id = 100n;
+  const Id = 101n;
   const dstChain = "TON".padEnd(64, ' ');
   const dstAsset = "Toncoin".padEnd(64, ' ');
   const dstAddress = "0QAS8JNB0G4zVkdxABCLVG-Vy3KXE3W3zz1yxpnfu4J-B40y".padEnd(64, ' ');
   const srcAsset = "ETH".padEnd(64, ' ');
   const srcReceiver = {"bits":"0x6364b23e8c34d46d0b68d20e0c1463230a9243a1dd710a7dd8b32dfb927af53a"};
-  const currentUnixTime = Math.floor(Date.now() / 1000) + 100;
+  const currentUnixTime = Math.floor(Date.now() / 1000) + 10;
   const timelock = DateTime.fromUnixSeconds(currentUnixTime).toTai64();   
-  const hashlock = "0xd4a671c0bb24f780c8ed7c13cfb6a554585bea038416afdcf806e73381db8417";        
+  const hashlock = "0x3b7674662e6569056cef73dab8b7809085a32beda0e8eb9e9b580cfc2af22a55";        
 
   const contractAddress = Address.fromB256(contractAddressString);
   const contractInstance = new Contract(contractAddress, contractAbi, wallet);
diff --git a/packages/fuel/scripts/redeem.ts b/packages/fuel/scripts/redeem.ts
index 872d200..dc3ae49 100644
--- a/packages/fuel/scripts/redeem.ts
+++ b/packages/fuel/scripts/redeem.ts
@@ -5,7 +5,7 @@ import * as path from 'path';
 const filePath = path.join(__dirname, '../out/release/fuel-abi.json');
 const contractAbi = JSON.parse(fs.readFileSync(filePath, 'utf-8'));
 
-const contractAddressString = '0x33dab65c45258fea05215fca2a2578fb94b13920d5a736e02ac9aae517b2bd96';
+const contractAddressString = '0x00f3dfc843089523a41a08a611ad39eef57de6ebdb58915840ed81d3fe9a5476';
 
 async function getWalletBalances() {
   const provider = await Provider.create('https://testnet.fuel.network/v1/graphql');
@@ -15,8 +15,8 @@ async function getWalletBalances() {
 
   const contractAddress = Address.fromB256(contractAddressString);
   const contractInstance = new Contract(contractAddress, contractAbi, wallet);
-  const Id = 1n;
-  const secret = 9065364567159659789812097500307188665539569649970302555505078182575840194842n;       
+  const Id = 101n;
+  const secret = 33648946896879551350753991616036334622602839139780100591470253765180571691018n;       
 
   try {
     const { transactionId, waitForResult } = await contractInstance.functions
diff --git a/packages/fuel/scripts/refund.ts b/packages/fuel/scripts/refund.ts
index 489795d..37ca59b 100644
--- a/packages/fuel/scripts/refund.ts
+++ b/packages/fuel/scripts/refund.ts
@@ -5,7 +5,7 @@ import * as path from 'path';
 const filePath = path.join(__dirname, '../out/release/fuel-abi.json');
 const contractAbi = JSON.parse(fs.readFileSync(filePath, 'utf-8'));
 
-const contractAddressString = '0x33dab65c45258fea05215fca2a2578fb94b13920d5a736e02ac9aae517b2bd96';
+const contractAddressString = '0x00f3dfc843089523a41a08a611ad39eef57de6ebdb58915840ed81d3fe9a5476';
 
 async function getWalletBalances() {
   const provider = await Provider.create('https://testnet.fuel.network/v1/graphql');
diff --git a/packages/fuel/src/main.sw b/packages/fuel/src/main.sw
index d04a279..52b75d2 100644
--- a/packages/fuel/src/main.sw
+++ b/packages/fuel/src/main.sw
@@ -9,6 +9,9 @@ use std::{
     call_frames::*,
     hash::*,
     storage::storage_vec::*,
+    b512::B512,
+    ecr::ec_recover_address,
+    bytes_conversions::{u64::*, u256::*, b256::*},
 };
 
 abi LayerswapV8 {
@@ -27,6 +30,9 @@ abi LayerswapV8 {
     #[storage(read,write)]
     fn add_lock(Id: u256, hashlock: b256, timelock: u64) -> u256; 
 
+    #[storage(read,write)]
+    fn add_lock_sig(signature: B512,Id: u256, hashlock: b256, timelock: u64) -> u256;
+
     #[payable]
     #[storage(read,write)]
     fn lock(Id: u256, 
@@ -117,8 +123,24 @@ fn has_htlc(Id: u256) -> bool {
     }
 }
 
+#[storage(read,write)]
+fn apply_lock(Id: u256, hashlock: b256, timelock: u64) -> u256 {
+    let mut htlc: HTLC = storage.contracts.get(Id).try_read().unwrap();
+    require(!htlc.refunded,"Already Refunded");
+    require(timelock > timestamp(),"Not Future Timelock");
+    require(htlc.hashlock == b256::from(0),"Hashlock Already Set");
+    htlc.hashlock = hashlock;
+    htlc.timelock = timelock;
+    storage.contracts.insert(Id, htlc);
+
+    log(TokenLockAdded  {Id: Id,
+                        hashlock: hashlock,
+                        timelock: timelock
+        });
+    Id
+}
+
 impl LayerswapV8 for Contract {
-    // TODO: reasearch for better approach
     #[storage(read,write)]
     fn initialize(salt: u256) -> bool{
         let num: u256 = storage.contractSeed.read();
@@ -204,8 +226,6 @@ impl LayerswapV8 for Contract {
     fn add_lock(Id: u256, hashlock: b256, timelock: u64) -> u256 {
         require(has_htlc(Id), "HTLC Does Not Exist");
         let mut htlc: HTLC = storage.contracts.get(Id).try_read().unwrap();
-        require(!htlc.refunded,"Already Refunded");
-        require(timelock > timestamp(),"Not Future Timelock");
         let sender = match msg_sender().unwrap() {
                         Identity::Address(addr) => addr,  
                         _ => {require(false, "No Allowance");
@@ -214,16 +234,19 @@ impl LayerswapV8 for Contract {
                               Address::from(0x0000000000000000000000000000000000000000000000000000000000000000) },     
                     };
         require(htlc.sender == sender, "No Allowance");
-        require(htlc.hashlock == b256::from(0),"Hashlock Already Set");
-        htlc.hashlock = hashlock;
-        htlc.timelock = timelock;
-        storage.contracts.insert(Id, htlc);
+        apply_lock(Id,hashlock,timelock)
+    }
 
-        log(TokenLockAdded  {Id: Id,
-                            hashlock: hashlock,
-                            timelock: timelock
-            });
-        Id
+    #[storage(read,write)]
+    fn add_lock_sig(signature: B512,Id: u256, hashlock: b256, timelock: u64) -> u256{
+        require(has_htlc(Id), "HTLC Does Not Exist");
+        let mut htlc: HTLC = storage.contracts.get(Id).try_read().unwrap();
+        let IdBytes: b256 = Id.into();
+        let timelockBytes: b256 = timelock.as_u256().into();
+        let message: [b256;3] = [IdBytes,hashlock,timelockBytes];
+        let messageHash = sha256(message);
+        require(htlc.sender == ec_recover_address(signature,messageHash).unwrap(),"Invalid Signature");
+        apply_lock(Id,hashlock,timelock)
     }
 
     #[payable]