Recognize Frozen ETP Transaction Outputs

Because of onchain-deposit, users can send FRONZEN ETP to any address. So the exchange platforms and wallet serivie prividers have to recognize this type of transaction outputs.

How to recognize frozen ETP transaction outputs?

A regular P2PKH (Pay to public key hash) output script looks like this:

dup hash160 [ 376485d30ed4e7d051f215f5eeeff4732b1075c6 ] equalverify checksig

A locked transaction however has the following output script:

[ 7062 ] numequalverify dup hash160 [ 4fd34a03c3e140700c9324202a335bda6b5fddc3 ] equalverify checksig

The first sqare brackets determine the locktime in number of blocks (hex encoded little endian).
A lock transaction also triggers the creation of a reward transaction that the miner of the block creates. That transaction has a coinbase input and a locked output.
Please make sure that you only accept P2PKH transaction outputs if you expect a regular payment or deposit. Otherwise the ETP will be locked for up to a year.

Solutions

• Solution 1: Write some code to identity the type of ETP transaction.We recommand to use regular expression as below to filter script:

  ^dup\ hash160\ \[ ([a-f0-9]+)\ \]\ equalverify\ checksig$

• Solution 2:
  A improved version of Metaverse Wallet already released on mvs.org, and improved source code was commited on github(#178).
  Added new filed ‘locked_height_range’ in JSON response for commands:

  gettx
  listtxs
  getblock
  fetch-tx

If the value of locked_height_range is non-zero, it means the ETP output is fronzen.

Example of NORMAL ETP output:

{
    "hash": "edfabf9651669645235ddeda824648409bf586b79722c4ebd54f6aaf53de58f8",
    "height": "719299",
    "inputs": [
        {
            "previous_output": {
                "hash": "0000000000000000000000000000000000000000000000000000000000000000",
                "index": "4294967295"
            },
            "script": "[ 03c3f90a ]",
            "sequence": "0"
        }
    ],
    "lock_time": "0",
    "outputs": [
        {
            "index": "0",
            "address": "MEVgP8kvucyR9523t71FVKSiZccQjeK4ki",
            "script": "dup hash160 [ 485810bf4d7c698938786c937aa12c467f8261a9 ] equalverify checksig",
            "locked_height_range": "0", // It means this ETP output is available.
            "value": "285240000",
            "attachment": {
                "type": "etp"
            }
        }
    ],
    "version": "1"
}

Example of FROZEN ETP output:

{
    "hash": "53e05539209c80bf36b9f729f4d8c0f240e55b320814fdb074029b6bd5d3e967",
    "height": "676276",
    "inputs": [
        {
            "previous_output": {
                "hash": "0000000000000000000000000000000000000000000000000000000000000000",
                "index": "4294967295"
            },
            "script": "[ 03b4510a ]",
            "sequence": "0"
        }
    ],
    "lock_time": "676274",
    "outputs": [
        {
            "index": "0",
            "address": "MFBEjD9QwgTxnRiUGd2qXATYxcReyG5ZtB",
            "script": "[ 7062 ] numequalverify dup hash160 [ 4fd34a03c3e140700c9324202a335bda6b5fddc3 ] equalverify checksig",
            "locked_height_range": "25200", // value is non-zero, It means FRONZEN ETP will be unlocked after how many blocks.
            "value": "9",
            "attachment": {
                "type": "etp"
            }
        }
    ],
    "version": "1"
}