Method and apparatus for maintaining the privacy of digital messages conveyed by public transmission.

摘要

A private message of m bits is conveyed from its sender to its receiver by transmission of a public message of m bits, transmission of a public reply of m bits, and another transmission of a public message of m bits such that only the intended receiver can easily recover the private message from the three public messages. This private message now available to both the sender and intended receiver also allows all subsequent private messages between these two points to require only one public message for each private message while maintaining the property that only the intended receiver of each message can easily recover the private message from each public message.