I thought this was an interesting experiment, so I tried it:
double-spending the 0-conf coinwallet "sweeper" spam.
Below is a quick write-up:
double-spending the 0-conf coinwallet "sweeper" spam.
Below is a quick write-up:
@elmad, this is an answer how to create the transaction without retrieving utxo from the blockchain
@basil00, you can use predefined 'k' for signing ECDSA. This saves some space in blockchain.
For example:
https://blockchain.info/tx/22af08a3eb8cf66d118d31af55bbc0862351d34734df03ddfa4ac1e1a9c2eec5
12 inputs, one output to OP_RETURN ----------- 1800 bytes
https://blockchain.info/tx/4d06062bb025886f4d8c2436aecfc4935d7f920b5e610592dc43e4026653912e
12 inputs, one output to p2pk ----------- 1686 bytes
See also
https://bitcointalk.org/index.php?topic=1118704
UPD:
And it would be better to use SIGHASH_NONE | SIGHASH_ANYONECANPAY instead of SIGHASH_ALL