#Hashed Time-Locked Contracts

A Hashed Time-Lock Contract (HTLC) is a set of transaction types that permits a designated party (the “sender/seller”) to LOCK funds by disclosing the preimage (secret) of a hash. It also permits a second party (the “recipient/buyer”) to CLAIM the funds, or after a timeout is reached enter a REFUND situation.

For a detailed explanation of how HTLC transaction works, please read our blog post here:

blog.ark.io

Not Found – Medium

#HTLC Lock

The purpose of this transaction is to lock funds of the sender and made them possible for retrieval by the recipient, if he knows the shared secret.

#Transaction Structure

#Signed JSON Payload

 1{
 2    "version": 2,
 3    "network": 23,
 4    "type": 8,
 5    "nonce": "2",
 6    "senderPublicKey": "020d272fab67c179a9e4df4d006344d3ca47fb531b4246b483373940f0603a9216",
 7    "fee": "10000000",
 8    "amount": "1",
 9    "recipientId": "ATNGUiu6sYRb7MXtdcVc7KjoyM6TdfuoC1",
10    "asset": {
11        "lock": {
12            "secretHash": "09b9a28393efd02fcd76a21b0f0f55ba2aad8f3640ff8cae86de033a9cfbd78c",
13            "expiration": {
14                "type": 1,
15                "value": 78740307
16            }
17        }
18    },
19    "signature": "11b1c06b4e5ba7c196f6f36fca2540275173a472e61581e949cd24a7cf5ee98af6a74f3c919f9b82a2e65b51b737bdf22f7a08ffcf52b88dc4a16d6ac5c10bfe",
20    "id": "f84efeab77224af8959301a7185597a7cfbfbc9a4d99cb021af62f3714feb9d3"
21}

#Serialized Payload

1ff02170100000008000200000000000000020d272fab67c179a9e4df4d006344d3ca47fb531b4246b483373940f0603a9216809698000000000000010000000000000009b9a28393efd02fcd76a21b0f0f55ba2aad8f3640ff8cae86de033a9cfbd78c01537bb104177f2a95c7076ea278776d8fcecc5b18e588976da611b1c06b4e5ba7c196f6f36fca2540275173a472e61581e949cd24a7cf5ee98af6a74f3c919f9b82a2e65b51b737bdf22f7a08ffcf52b88dc4a16d6ac5c10bfe

#Deserialized Hex Payload

#HTLC Claim

The purpose of this transaction is for the recipient to CLAIM funds from the sender - if he knows the shared secret.

#Transaction Structure

#Signed JSON Payload

 1{
 2    "version": 2,
 3    "network": 23,
 4    "type": 9,
 5    "nonce": "3",
 6    "senderPublicKey": "039d974aa6feff6a19fde69a8a8b25b991798e98252765a887118ba61218f473a2",
 7    "fee": "0",
 8    "amount": "0",
 9    "asset": {
10        "claim": {
11            "lockTransactionId": "f84efeab77224af8959301a7185597a7cfbfbc9a4d99cb021af62f3714feb9d3",
12            "unlockSecret": "f5ea877a311ced90cf4524cb489e972f"
13        }
14    },
15    "signature": "c2b9f3655174c13686dde428cf18d5d18f465712985a7086b04860457e8d2db64443083bdf69fdc5b94dcd2c4c722606cf0e058ffae98d8f9f069177c5c189ab",
16    "id": "d8acf49eba509e94494f454a86add1fab8b2130f223c9cc25e8e92745a584813"
17}

#Serialized Payload

1ff02170100000009000300000000000000039d974aa6feff6a19fde69a8a8b25b991798e98252765a887118ba61218f473a2000000000000000000f84efeab77224af8959301a7185597a7cfbfbc9a4d99cb021af62f3714feb9d36635656138373761333131636564393063663435323463623438396539373266c2b9f3655174c13686dde428cf18d5d18f465712985a7086b04860457e8d2db64443083bdf69fdc5b94dcd2c4c722606cf0e058ffae98d8f9f069177c5c189ab

#Deserialized Hex Payload

#HTLC Refund

The purpose of this transaction is for the sender to receive back his locked funds, in the case of recipient not claiming them.

#Transaction Structure

#Signed JSON Payload

 1{
 2    "version": 2,
 3    "network": 23,
 4    "type": 10,
 5    "nonce": "3",
 6    "senderPublicKey": "037fc2e14f626586722a4f9e00dca2efbc4ac409c1ca63bc4309f56184265f95d5",
 7    "fee": "0",
 8    "amount": "0",
 9    "asset": {
10        "refund": {
11            "lockTransactionId": "c62bd36c162dd0116a08bf8a75cd6d1f83b8f5f1e17e89c8231ebb7af595f64d"
12        }
13    },
14    "signature": "ae272f4650ee1d46260b8f62e7e956af33cd25587318fed056aec8e9d518e2394d0fd3166d8cd8506abfc303c644041a4bab35daf7c8aaa77f916ef09dc90336",
15    "id": "4d9ee7f8b27999d4ce7acf6afee08e3da67bc1fca258f2bd17e426933a846602"
16}

#Serialized Payload

1ff0217010000000a000300000000000000037fc2e14f626586722a4f9e00dca2efbc4ac409c1ca63bc4309f56184265f95d5000000000000000000c62bd36c162dd0116a08bf8a75cd6d1f83b8f5f1e17e89c8231ebb7af595f64dae272f4650ee1d46260b8f62e7e956af33cd25587318fed056aec8e9d518e2394d0fd3166d8cd8506abfc303c644041a4bab35daf7c8aaa77f916ef09dc90336

#Deserialized Hex Payload