Question

AES is a block cipher, meaning that it encrypts blocks of 128 bits of data at a time. If every block is encrypted using the same key and information from previous blocks is not mixed in with the current block, which of the following describe how confidentiality, sender authenticity, or message integrity can be compromised?

A. Sender authenticity is compromised because an attacker can construct a new message using blocks from previous messages it intercepted over the network
B. Message integrity and confidentiality might be compromised because it is possible to recover any key used more than once
C. Confidentiality might be compromised because two blocks with the same ciphertext must have the same plaintext
D. No AES communications have message integrity because it is a symmetric cipher

Answer 1

The answer is B.

Step-by-step explanation:

Message integrity and confidentiality might be compromised because it is possible to recover any key used more than once