Certified Ethical Hacker (CEH v12) — Question 98

Alice needs to send a confidential document to her coworker, Bryan. Their company has public key infrastructure set up. Therefore, Alice both encrypts the message and digitally signs it. Alice uses _______________ to encrypt the message, and Bryan uses _______________ to confirm the digital signature.

Answer options

• A. Bryan’s public key; Bryan’s public key
• B. Alice’s public key; Alice’s public key
• C. Bryan’s private key; Alice’s public key
• D. Bryan’s public key; Alice’s public key

Correct answer: D

Explanation

The correct answer is D because Alice uses Bryan's public key to encrypt the message, ensuring only Bryan can decrypt it with his private key. Bryan then uses Alice's public key to verify her digital signature, confirming that the document has not been altered and is indeed from Alice. The other options incorrectly suggest using the same key for both encryption and signature verification, which does not align with public key infrastructure principles.