What is a digital signature?

• A. An electronic signature for contracts
• B. A signature that ensures performance quality
• C. An electronic signature ensuring authenticity
• D. A method to collect user consent

Answer: (C)

A digital signature is a cryptographic technique that provides a secure way to verify the authenticity and integrity of a message, document, or software. It employs algorithms that generate a unique hash of the data being signed, which is then encrypted with the sender’s private key. When the recipient receives the signed data, they can decrypt the hash using the sender's public key, thus confirming both the source of the message and that it has not been tampered with during transmission.

This definition highlights why the emphasis on authenticity is crucial. Digital signatures serve a critical role in ensuring that the person or entity who claims to have signed the data genuinely did so and that the content remains intact. It prevents impersonation and guarantees that the message has not been altered by anyone else.

While an electronic signature may capture a person's intent to agree to terms, it does not inherently provide the same level of security or verification as a digital signature. Options referring to performance quality or methods to collect consent lack the specific focus and cryptographic mechanisms inherent in a digital signature, which is fundamentally about ensuring authenticity and integrity.