Secure Communications Over Insecure Channels.

The article discusses the possibility of selecting a key over open communications channels in such a fashion that communications security is maintained. People have been communicating with each other for many millennia. They often wish to communicate secretly. People have employed a number of ciphers and codes in attempts to keep their correspondence secret. The modern digital computer has made it possible to create ciphers which are, in practical terms, unbreakable. Underlying this success has been a very definite paradigm, which makes very definite assumptions about the nature of the encryption process, and the conditions under which secret communications can take place. It is the purpose of this paper to consider this paradigm, and to question the assumptions which underlie it. The body of the paper begins with an explanation of the traditional paradigm and then develops a new paradigm, which differs significantly from the traditional one. The new paradigm has implications for network security. In a computer network, with many users with diverse needs, security is difficult to maintain.