CISSP – Information Systems Security Architecture Professional (ISSAP) — Question 86

In which of the following cryptographic attacking techniques does an attacker obtain encrypted messages that have been encrypted using the same encryption algorithm?

Answer options

• A. Chosen plaintext attack
• B. Ciphertext only attack
• C. Chosen ciphertext attack
• D. Known plaintext attack

Correct answer: B

Explanation

The correct answer is B, as a ciphertext-only attack involves the attacker analyzing encrypted messages without any corresponding plaintext. The other options involve different scenarios where the attacker has some level of control or knowledge about the plaintext or ciphertext, which does not align with the nature of a ciphertext-only attack.