Question

A ____________________ is less effective, but much more likely for the attacker since the attacker only has access to a collection of ciphertexts. NOTE: The attacker ONLY has access to the ciphertext of messages.

A) Brute-force attack
B) Known-plaintext attack
C) Ciphertext-only attack
D) Frequency analysis attack

Answer 1

A ciphertext-only attack is less effective, but much more likely for the attacker since the attacker only has access to a collection of ciphertexts. An example of a ciphertext-only attack is frequency analysis.

Step-by-step explanation:

A ciphertext-only attack is less effective, but much more likely for the attacker since the attacker only has access to a collection of ciphertexts. In this type of attack, the attacker does not have any knowledge of the plaintext message or any other information about the encryption process. An example of a ciphertext-only attack is frequency analysis.

In frequency analysis, the attacker analyzes the frequency of individual letters or character patterns in the ciphertext to try to infer information about the original plaintext. For example in the English language, the letter 'e' is the most frequently used letter so if the attacker notices a particular cipher symbol that occurs most frequently in the ciphertext they might guess that it corresponds to the letter 'e' in the plaintext.