1. Which description about Information Theoretic Security is NOT correct? (5 points) ( )

A. Ciphertext should reveal no "information about Plaintext (except for its length).

B. One-Time Pad can achieve Information Theoretic Security.

C. If the cipher can achieve Information Theoretic Security, the probability distribution of the

plaintext would change after knowing the ciphertext.

D. To achieve Information Theoretic Security, the key should be completely random and at least as

long as the plaintext/ciphertext.