What is Digital signature?
Cryptographic proof that the holder of a private key authorised a specific transaction, verifiable by anyone with the public key.
Signatures bind to the exact transaction, so they cannot be lifted and reused elsewhere. Bitcoin has used ECDSA since launch and added Schnorr signatures with Taproot.
Schnorr signatures can be aggregated, which makes multi-party spends cheaper and less distinguishable on-chain from single-key ones.
Related terms
Private key
The secret number that authorises spending from an address. Whoever holds it controls the coins…
Keys & custodyPublic key
The value derived from a private key that lets anyone verify a signature without learning the key itself.
NetworkTaproot
A 2021 soft fork adding Schnorr signatures and a scheme that makes complex spending conditions look like…
This definition is part of the Bitcoin Logical glossary. For the fuller explanation, start with Apprendre, or see the live numbers on Le Signal Bitcoin.