Dr. Diffie is best known for his 1975 concept of public key cryptography, for which the Swiss Federal Institute of Technology awarded him a Doctorate in Technical Sciences (Honoris Causa) in 1992. Since 1993, Dr. Diffie has worked in public policy opposition to limitations on business and personal use of cryptography, testifying twice to the U.S. Congress and Senate. His awards are many and include IEEE Information Society Golden Jubilee Award for invention of the Diffie-Hellman key exchange protocol. Dr. Diffie is co-author of the book, Privacy on the Line: The Politics of Wiretapping and Encryption.