Which of the following is true for digital signatures?

A.
The sender encrypts the hash with a public key

B.
The sender encrypts the hash with a private key

C.
The sender encrypts the plaintext with a public key

D.
The sender encrypts the plaintext with a private key

Explanation:
Answer B is correct; the sender generates a hash of the plaintext and encrypts the hash with a private key. The recipient decrypts the hash with a public key.

Incorrect Answers and Explanations: A, C, and D: Answers A, C, and D are incorrect. The sender encrypts the hash with the private key, not public. The plaintext is hashed, and not encrypted.