64 bit arithmetic soft fork

This BIP describes a new set of arithmetic opcodes (OP_ADD64, OP_SUB64, OP_MUL64, OP_DIV64, OP_NEG64, OP_LESSTHAN64, OP_LESSTHANOREQUAL64, OP_GREATERTHAN64, OP_GREATERTHANOREQUAL64) that allows 64 bit signed integer math in the bitcoin protocol.

This BIP also describes a set of conversion opcodes (OP_SCRIPTNUMTOLE64, OP_LE64TOSCRIPTNUM, OP_LE32TOLE64) to convert existing bitcoin protocol numbers (CScriptNum) into 4 and 7 byte little endian representations.




Credit: Andrew Poelstra, Sanket Kanjalkar, Chris Stewart

Btcd consensus bugs due to usage of signed transaction version

Btcd used the signed transaction version in both the BIP 68 5 and BIP 112 1 logic without a prior cast to uint32. As consequence, transactions with negative versions are incorrectly treated as not enforcing the BIP 68 rules or incorrectly rejected for use of OP_CHECKSEQUENCEVERIFY (BIP 112).


bitcoin-s fix


Credit: dergoegge

BIP friction process


Credit: ajtowns

Coinjoin & Payjoin UI/UX

Credit: KeithM

Recent work adding coinjoin & payjoin support to SeedSigner holds lessons about bitcoin wallet UI/UX.




This project illustrates how the engineering efforts going into ZK rollups on other blockchains like Ethereum can apply with BitVM to produce a rollup system on Bitcoin.