This paper, provided by Ronald L. Rivest, professor of Electrical Engineering and Computer Science at the Massachusetts Institute of Technology, proposes a new method of computer message security. The method is called "chaffing and winnowing." Messages are broken up into packets and each packet is appended with a "message authentication code" (MAC). Then "chaff," fake packets with fake MACs, is intermingled with the true packets. The receiver of the message uses a secret code (shared with the sender) to "winnow" the chaff in order to receive the true message. Since this process does not involve encryption, it is proposed that it will circumvent "attempts by law enforcement to regulate confidentiality by regulating encryption."