This paper describes Needham-Schroeder type authentication and key-distribution protocols that do not use encryption or decryption. The new protocols use polynomial interpolation instead, and one-way hash functions if necessary. These protocols are simple, elegant, and efficient when compared with conventional protocols based on encryption. One significant advantage of this new approach is that critical security properties of the protocols no longer depend on an underlying cryptosystem being secure. Protocols for secure broadcast and for secure communication are also developed using the same technique.

• sri-csl-tr94-08.pdf
• sri-csl-tr94-08.ps