Certified Ethical Hacker (CEH v10) — Question 1

In which of the following cryptography attack methods, the attacker makes a series of interactive queries, choosing subsequent plaintexts based on the information from the previous encryptions?

Answer options

• A. Chosen-plaintext attack
• B. Ciphertext-only attack
• C. Adaptive chosen-plaintext attack
• D. Known-plaintext attack

Correct answer: A

Explanation

The correct answer is A, Chosen-plaintext attack, as it directly involves the attacker selecting plaintexts based on prior results. The other options do not describe this interactive querying process: B refers to a scenario where only ciphertext is available, C involves adaptability in queries beyond just chosen plaintexts, and D relies on previously known plaintexts without the query process.