Which statement accurately describes the relationship between a private key and a digital signature?

• A. The digital signature is created by encrypting the hash of the data with the private key.
• B. The private key encrypts the entire message for confidentiality.
• C. The digital signature is independent of the private key.
• D. The private key is not used in signing.

Answer: (D)

Digital signatures rely on public-key cryptography to prove who created the data and that it hasn’t been altered. The signing process typically hashes the data and then uses the private key to encrypt that hash. That encrypted hash becomes the digital signature. Anyone with the corresponding public key can decrypt the signature to obtain the hash and compare it to a fresh hash of the received data; if they match, the data is intact and the signer is verified. The private key is specifically used for signing, not for encrypting the entire message for confidentiality.