A DIGITAL SIGNATURE provides which security property?

1. A DIGITAL SIGNATURE binds a message to a SIGNER and proves the message has not changed. 2. Properties provided: • AUTHENTICITY: the signer's private key produced it (and we verify with their public key). • INTEGRITY: any change to the message invalidates the signature. • NON-REPUDIATION: the signer cannot later deny signing (they alone hold the private key). 3. Algorithms: RSA-SSA, ECDSA, EdDSA. 4. USE CASES: code signing, document signing, X.509 TLS certificates, JWT tokens. 5. Option A is what encryption provides; the others are unrelated. _Source: Boneh & Shoup, §13 (Digital signatures)._