Certified Information Systems Auditor (CISA) — Question 727

Which of the following BEST enables an organization to verify whether an encrypted message sent by a client has been altered?

Answer options

• A. The date and time stamp of the received message
• B. The digital signature
• C. The sender’s private key
• D. The message header

Correct answer: B

Explanation

The digital signature (B) allows the recipient to verify both the authenticity of the sender and the integrity of the message by checking if it has been altered. The other options do not provide a mechanism for verifying message integrity; for instance, a timestamp (A) does not indicate changes to the message content, while the sender's private key (C) is used for signing and not for verification, and the message header (D) lacks the necessary information to confirm alterations.