Chaffing

A cryptography technique that is used to maintain confidentiality and security without the need for encryption over an unsecured network. Chaffing involves taking a group of authenticated message blocks (wheat) and inserting a bunch of chaff blocks with random contents and MAC fields. This means that the chaff blocks appear to an adversary to be as genuine as the wheat blocks, necessitating authentication on each block. The sender can make cracking the message computationally impossible by customising the number of chaff blocks sent to the transmission. This helps to protect against 51% attacks.