Digital Signatures

Correct Answer: Report the issue to security officer

The correct answer is to report the issue to the security officer. Ignoring the mismatch could lead to compromised data integrity, forwarding the document would spread an untrusted file, and both deleting and manually editing the signature would not resolve the issue and could cause further complications. Creating a new document might not capture the correct digital signatures.

Correct Answer: Examine the signature and its validation process

Examining the digital signature and its validation process would help identify if an attacker has compromised any aspect of the signing process. Contacting the sender, assuming the attacker's access to private keys, checking certificate revocation, assuming social engineering, or requesting a new public key will not effectively lead to identifying the method the attacker used.

Correct Answer: Verify with the signer's public key

To confirm the authenticity of a digitally signed document, the recipient should verify it using the signer's public key. Other options like checking the document's checksum, inspecting properties, comparing versions, analyzing metadata, and requesting the sender's private key are ineffective or not applicable.