3Rivest R. The MD5 Message-Digest Algorithm. RFC 1321, April 1992.
4Rivest R. The MD4 Message-Digest Algorithm. RFC 1320, April 1992.
5Haller N. The S/KEY One-Time Password System//Proceedings of the ISOC Symposium on Network and Distributed System Security. February 1994, San Diego, CA.
6Haller N, Atkinson R. On Internet Authentication. RFC 1704, October 1994.
7Haller N. The S/KEY One-Time Password System. RFC 1760, February 1995.
