Which one of the following, if embedded within the ciphertext, will decrease the likelihood of a
message being replayed?
A.
Stop bit
B.
Checksum
C.
Timestamp
D.
Digital signature
Explanation:
CBC is the CBC mode of some block cipher, HMAC is a keyed message digest, MD is a plain message
digest, and timestamp is to protect against replay attacks. From the OpenSSL project
http://www.mail-archive.com/openssl-users@openssl.org/msg23576.html