Symmetric ciphers encrypt plaintext into ciphertext using a secret key. Confusion and diffusion are two cryptographic properties of a cipher to make cryptanalysis difficult. Which of the following statements is not true?
A. Substitution algorithms support confusion
B. Confusion applies to both stream and block cipher
C. Confusion makes recovering the secret key by the ciphertext-only attack more difficult
D. Confusion reduces patterns and obscures the relationship between plaintext and ciphertext

Kindly be reminded that the suggested answer is for your reference only. It doesn’t matter whether you have the right or wrong answer. What really matters is your reasoning process and justifications.

My suggested answer is D. Confusion reduces patterns and obscures the relationship between plaintext and ciphertext.

Confusion reduces patterns and obscures the relationship between the key and ciphertext.