In 1976, Whitfield Diffie, Martin Hellman, and Ralph Merkle developed public key cryptography (PKC), an innovative new method for securing electronic communications. PKC provides security on the otherwise highly insecure Internet, making it vital to such areas as e-commerce.
In traditional cryptography, the same key is used both to encrypt and decrypt a message. To preserve secrecy, keys must be exchanged via couriers or other secure means. With PKC, each individual has his own unique key pair consisting of a public key and a private key. Only the public key needs to be exchanged, eliminating the need for couriers. If a person's public key is used to encrypt a message, then only his corresponding private key can decrypt it, providing privacy. Likewise, if his private key is used to sign (encrypt) a message, the corresponding public key can authenticate (decrypt) the message.
Hellman is professor emeritus at Stanford, and his current focus is the application of risk analysis to nuclear deterrence. Born in New York City, he received his B.E. from New York University and his M.S. and Ph.D. from Stanford.