Digital Signature

Cryptography · Intermediate

A cryptographic value produced with a private key so others can use the matching public key to verify the signer and detect changes.

It is closer to a seal than to secrecy. Anyone with the public key can check it. It does not hide the message unless encryption is added separately.

Example: A software author signs an update. Your computer rejects the file if the signature does not match the author's public key.

Common misconception

A signature does not encrypt the message. It supports authenticity and integrity.