Which of the following is the MOST likely cause of users being unable to verify a single user’s email signature and that user being unable to decrypt sent messages?
A. Unmatched key pairs B. Corrupt key escrow C. Weak public key D. Weak private key
Answer: A
Explanation: In a PKI the sender encrypts the data using the receiver’s public key. The receiver decrypts the data using his own private key. The sender and receiver must have a matching key in order for the receiver to decrypt the data.