Ralph Merkle realized public-key cryptography (PKC) was possible in 1974 as an undergraduate at U.C. Berkeley. He worked alone until he joined forces with Whitfield Diffie and Martin Hellman in 1976. This fruitful collaboration saw the development of this innovative new method for securing electronic communications.
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.
Merkle is a Senior Research Fellow with the Institute for Molecular Manufacturing, is on the faculty of Singularity University, co-founded the Nanofactory Collaboration and is an Alcor Director. Born and raised in California, he first attended the University of California, Berkeley and then went on to Stanford for his Ph.D.