Born June 5th, 1944, Diffie is a cryptographer best known for inventing public key cryptography in cooperation with Martin Hellman and Ralph Merkle in 1976.
The method of public key distribution he helped create would later be called the Diffie-Hellman key exchange
http://en.wikipedia.org/wiki/Whitfield_Diffie
http://en.wikipedia.org/wiki/Diffie-Hellman_key_exchange