Sighash
bitcoin · scripting
Signature-hash flags that define which transaction parts a signature commits to in Bitcoin-style scripts.
Sighash, short for signature hash, defines the transaction data covered by a signature. Common modes include ALL, NONE, SINGLE, and ANYONECANPAY variants, which control whether the signature commits to all inputs and outputs or only selected parts.
Sighash flags enable advanced contracts and multi-party transaction construction, but they are consensus-sensitive and chain-specific. Wallets should choose flags carefully because signing too little can allow another party to change parts of the transaction.
Related terms
Signature
→A cryptographic proof that a message was authorized by the holder of a private key.
cryptography
Transaction
→A serialized state transition that a blockchain can validate, relay, and include in a block.
blockchain · technical
Opcode
→An encoded instruction interpreted by a virtual machine or transaction script engine.
technical · scripting