Glossary
Digital Signature
A cryptographic stamp that proves a specific private key authorized a specific message — and lets anyone verify it with the matching public key.
A digital signature binds together a message, a private key, and an output (the signature itself) such that anyone holding the matching public key can verify the signature was produced by that private key for that exact message.
In blockchains, every transaction carries a signature that proves the sender authorized exactly what is being sent. Tampering with the message after signing invalidates the signature, so the network can trust the signed payload without trusting the messenger.