Please Help Me Double SPend

[paulb787]

I just recently upgraded electrum to the latest version. I use it with my trezor. For some reason it sent this transaction with a horribly low fee.

Is there anyway that I can generate a raw transaction to double spend? The trick is I need to sign it with my trezor? Is this possible?
https://blockchain.info/tx/f128aab7a68e803f84fd7d94b2de8873745d21ce709063e3b964fcaca7273a0f

Thanks,
Paul

[1714940750]

1714940750

[1714940750]

1714940750

[1714940750]

1714940750

[shorena]

I just recently upgraded electrum to the latest version. I use it with my trezor. For some reason it sent this transaction with a horribly low fee.

Is there anyway that I can generate a raw transaction to double spend? The trick is I need to sign it with my trezor? Is this possible?
https://blockchain.info/tx/f128aab7a68e803f84fd7d94b2de8873745d21ce709063e3b964fcaca7273a0f

Thanks,
Paul

double spend 1o1

take the raw TX -> https://blockchain.info/tx/f128aab7a68e803f84fd7d94b2de8873745d21ce709063e3b964fcaca7273a0f?format=hex

decode it (e.g. using bitcoin core):

Code:

{
  "txid": "f128aab7a68e803f84fd7d94b2de8873745d21ce709063e3b964fcaca7273a0f",
  "hash": "f128aab7a68e803f84fd7d94b2de8873745d21ce709063e3b964fcaca7273a0f",
  "size": 192,
  "vsize": 192,
  "version": 1,
  "locktime": 0,
  "vin": [
    {
      "txid": "b6c57e3ac43691343e47753ee2d7ce894ec6889cc48cd8b2888bb4b28f01e9e0",
      "vout": 1,
      "scriptSig": {
        "asm": "3045022100feaf323ba4eb8ea1a00ba5c1d67e4ec04fc4ab469f5484fdf5a94c44fb6b731002204df83d8358c6626f8f7fc0aaed81032ab83b03e5188255169db05fc98153f651[ALL] 02d3eec7636c06f76aa70693705c8e5eaaad156076d1050fe4984b2c2ed370ec50",
        "hex": "483045022100feaf323ba4eb8ea1a00ba5c1d67e4ec04fc4ab469f5484fdf5a94c44fb6b731002204df83d8358c6626f8f7fc0aaed81032ab83b03e5188255169db05fc98153f651012102d3eec7636c06f76aa70693705c8e5eaaad156076d1050fe4984b2c2ed370ec50"
      },
      "sequence": 4294967295
    }
  ],
  "vout": [
    {
      "value": 1.12254704,
      "n": 0,
      "scriptPubKey": {
        "asm": "OP_DUP OP_HASH160 7f04594f277ea3c930f31a3acc819872c8426f84 OP_EQUALVERIFY OP_CHECKSIG",
        "hex": "76a9147f04594f277ea3c930f31a3acc819872c8426f8488ac",
        "reqSigs": 1,
        "type": "pubkeyhash",
        "addresses": [
          "1Cac2XZGmUv3NNxuaqTm81iDMfyDG5kLmH"
        ]
      }
    }
  ]
}

Take you favorite boiler:

Code:

"[
{\"txid\":\"1\",\"vout\":23},
{\"txid\":\"2\",\"vout\":4},
{\"txid\":\"3\",\"vout\":1},
{\"txid\":\"4\",\"vout\":0}
]"
"{\"1addr\":0.00001234}"

and replace as needed with the data from the decoded tx:

Code:

"[
{\"txid\":\"b6c57e3ac43691343e47753ee2d7ce894ec6889cc48cd8b2888bb4b28f01e9e0\",\"vout\":1}
]"
"{\"1Cac2XZGmUv3NNxuaqTm81iDMfyDG5kLmH\":1.12264304}"

estimate the size (192 byte) and take a current fee prediction, e.g. from -> https://bitcoinfees.21.co/ (100 satoshi per byte) and substract from the amount to send.

1.12264304 - (100*192)/10⁸ = 1.12240000, make it round to add a little extra

Code:

"[
{\"txid\":\"b6c57e3ac43691343e47753ee2d7ce894ec6889cc48cd8b2888bb4b28f01e9e0\",\"vout\":1}
]"
"{\"1Cac2XZGmUv3NNxuaqTm81iDMfyDG5kLmH\":1.1224}"

make it a raw transaction (e.g. using bitcoin core)

Code:

0100000001e0e9018fb2b48b88b2d88cc49c88c64e89ced7e23e75473e349136c43a7ec5b60100000000ffffffff0180a5b006000000001976a9147f04594f277ea3c930f31a3acc819872c8426f8488ac00000000

Decode it to double check you didnt fuck it up somewhere.

Code:

{
  "txid": "ebfe9c81f5703412c599397e765327af5158dd594853c9b6a9cb84d11e7cef73",
  "hash": "ebfe9c81f5703412c599397e765327af5158dd594853c9b6a9cb84d11e7cef73",
  "size": 85,
  "vsize": 85,
  "version": 1,
  "locktime": 0,
  "vin": [
    {
      "txid": "b6c57e3ac43691343e47753ee2d7ce894ec6889cc48cd8b2888bb4b28f01e9e0",
      "vout": 1,
      "scriptSig": {
        "asm": "",
        "hex": ""
      },
      "sequence": 4294967295
    }
  ],
  "vout": [
    {
      "value": 1.12240000,
      "n": 0,
      "scriptPubKey": {
        "asm": "OP_DUP OP_HASH160 7f04594f277ea3c930f31a3acc819872c8426f84 OP_EQUALVERIFY OP_CHECKSIG",
        "hex": "76a9147f04594f277ea3c930f31a3acc819872c8426f8488ac",
        "reqSigs": 1,
        "type": "pubkeyhash",
        "addresses": [
          "1Cac2XZGmUv3NNxuaqTm81iDMfyDG5kLmH"
        ]
      }
    }
  ]
}

sign it

- cant, dont have the priv. key -

broadcast it after enough time has passed (usually 72 hours) so the network has forgotten about the first transaction or contact a miner directly.

Not sure what exact format you need for electrums .txn files.

[jackg]

Do you want this confirming or do you want to cancel it and resend it with a higher fee.
There is usually an option to "abandon transaction" in wallets, I'm not sure about one in electrum.

You could use this tool to increase the speed of your transaction (if your fee is high enough).

[shorena]

Do you want this confirming or do you want to cancel it and resend it with a higher fee.
There is usually an option to "abandon transaction" in wallets, I'm not sure about one in electrum.

You could use this tool to increase the speed of your transaction (if your fee is high enough).

The fee is probably too low, but it might help to get the double spend confirmed.

Found the electrum file format, you should be able to save the below in a file "unconfirmed.txn" and open it with electrum. Make sure you verify what you see before you sign (I edited it slightly from above).

Code:

{
    "hex": "0100000001e0e9018fb2b48b88b2d88cc49c88c64e89ced7e23e75473e349136c43a7ec5b60100000000ffffffff024063a106000000001976a9147f04594f277ea3c930f31a3acc819872c8426f8488ac40420f00000000001976a91428b7bf2161bfb369270fcace10d101827071ea2488ac00000000", 
    "complete": false, 
    "final": true
}

[steven0021]

With a fee of 50 satoshi per byte, your transaction will probably confirm before you'll be able to broadcast the transaction without the whole network rejecting it.

Just wait or use the site linked above. I'd submit it myself but I just expired my VPN (afraid of IP tracing).

The fee is probably too low, but it might help to get the double spend confirmed.

Actually, the minimal fee for ViaBTC's accelerator is 10 satoshi per byte. Yeah.

[shorena]

With a fee of 50 satoshi per byte, your transaction will probably confirm before you'll be able to broadcast the transaction without the whole network rejecting it.

Just wait or use the site linked above. I'd submit it myself but I just expired my VPN (afraid of IP tracing).

The fee is probably too low, but it might help to get the double spend confirmed.

Actually, the minimal fee for ViaBTC's accelerator is 10 satoshi per byte. Yeah.

I somehow read it as 960 satoshi fee, not 9600. Yeah, the double spend is probably not need at all, just some time.

[jackg]

With a fee of 50 satoshi per byte, your transaction will probably confirm before you'll be able to broadcast the transaction without the whole network rejecting it.

Just wait or use the site linked above. I'd submit it myself but I just expired my VPN (afraid of IP tracing).

The fee is probably too low, but it might help to get the double spend confirmed.

Actually, the minimal fee for ViaBTC's accelerator is 10 satoshi per byte. Yeah.

I somehow read it as 960 satoshi fee, not 9600. Yeah, the double spend is probably not need at all, just some time.

From what I remember, the fee on electrum wallets does not go below ~1000 satoshi. I tried testing the network by sending a transaction without any fees and it used a randomely plucked number of about 1000 satoshi to append the transaction to the network. (I remember tat transaction was about double the size of this one and took ten hours to confirm so this one should confirm within at least a few blocks - I think the estimate for 50 sat/KB is a maximum of about 3 hours as a maximum so it's still quite fast).

I'll broadcast the transaction to viabtc in a moment if it hasn't been confirmed yet.

[shorena]

Its confirmed now.

[paulb787]

thanks guys!

[fikihafana]

thanks guys!

is it work (i mean trick from shorena) ? i want to know for learning purpose

[Coding Enthusiast]

thanks guys!

is it work (i mean trick from shorena) ? i want to know for learning purpose

It is nothing strange, he is just making a Raw Unsigned Transaction with the same input and outputs (If you really want to learn read this) but changed the amount to send (hence increasing the fee).
And you can use any tool for that such as https://coinb.in/#newTransaction or even my buggy beta tool Link



Result

Code:

0100000001e0e9018fb2b48b88b2d88cc49c88c64e89ced7e23e75473e349136c43a7ec5b6010000001901ff16fd001afdcb1b31a0b907a050860f4a1ff159b89cf216ffffffff0180a5b006000000001976a9147f04594f277ea3c930f31a3acc819872c8426f8488ac00000000

@shorena
You didn't need to make a .txn file. Electrum has an option (Tools > Load Transaction > From text) for entering raw transactions.
Also for some reason Electrum does not accept ScriptSig that is empty, or anything other than 01ff16fd00 {hash} (you can see the difference in what I have made above)

[jackg]

thanks guys!

is it work (i mean trick from shorena) ? i want to know for learning purpose

It is nothing strange, he is just making a Raw Unsigned Transaction with the same input and outputs (If you really want to learn read this) but changed the amount to send (hence increasing the fee).
And you can use any tool for that such as https://coinb.in/#newTransaction or even my buggy beta tool Link



Result

Code:

0100000001e0e9018fb2b48b88b2d88cc49c88c64e89ced7e23e75473e349136c43a7ec5b6010000001901ff16fd001afdcb1b31a0b907a050860f4a1ff159b89cf216ffffffff0180a5b006000000001976a9147f04594f277ea3c930f31a3acc819872c8426f8488ac00000000

@shorena
You didn't need to make a .txn file. Electrum has an option (Tools > Load Transaction > From text) for entering raw transactions.
Also for some reason Electrum does not accept ScriptSig that is empty, or anything other than 01ff16fd00 {hash} (you can see the difference in what I have made above)

Did you do that before it was confirmed? Because I did also put the transaction onto that accelerator to see if that would work?
Nethertheless, it should have confimed fairly quickly based on the transaction fee size.

[Coding Enthusiast]

♯
Did you do that before it was confirmed? Because I did also put the transaction onto that accelerator to see if that would work?
Nethertheless, it should have confimed fairly quickly based on the transaction fee size.

I don't understand your question!
My comment is 2 days after the OP's tx was confirmed, and I am only doing what Shorena did with a GUI (my own open source tool), and what we did is making a raw unsigned transaction with the same inputs and outputs but with a different fee.
To use the transaction OP still needed to sign it with his private key!

[jackg]

♯
Did you do that before it was confirmed? Because I did also put the transaction onto that accelerator to see if that would work?
Nethertheless, it should have confimed fairly quickly based on the transaction fee size.

I don't understand your question!
My comment is 2 days after the OP's tx was confirmed, and I am only doing what Shorena did with a GUI (my own open source tool), and what we did is making a raw unsigned transaction with the same inputs and outputs but with a different fee.
To use the transaction OP still needed to sign it with his private key!

Oh... Erm sorry?
I thought you were the OP.
Otherwise there'd not really be any other reason to post here stating that once the trasnaction had been confirmed.

[Coding Enthusiast]

♯
Oh... Erm sorry?
I thought you were the OP.
Otherwise there'd not really be any other reason to post here stating that once the trasnaction had been confirmed.

Well, I was just answering fikihafana (which seems to be a signature spammer!) since he said "learning purpose" and also I added two rather important things at the end of my comment if you take another look.

[jackg]

♯
Oh... Erm sorry?
I thought you were the OP.
Otherwise there'd not really be any other reason to post here stating that once the trasnaction had been confirmed.

Well, I was just answering fikihafana (which seems to be a signature spammer!) since he said "learning purpose" and also added two rather important things at the end of my comment if you take another look.

I'm not sure what bit you're referring to about him adding two thing at the end of the comment? Could you PM the link to that maybe (if you want me to find it).

Possibly a spammer due to the "learning purposes" or maybie just a newbie here as double spending was a problem a while back as it could be manipulated so that both transactions were confirmed in some way (or that was how I understood it). Anyway, that flaw was "fixed" so is no longer a problem.