Whitfield Diffie

Whitfield Diffie is an American cryptographer who, together with Martin Hellman, co-invented public-key cryptography in a landmark 1976 paper titled New Directions in Cryptography. Before their work, secure communication generally required two parties to share a secret key in advance through some trusted channel; Diffie and Hellman showed that two parties could instead establish a shared secret over an insecure channel using a mathematical method now called Diffie-Hellman key exchange, without ever transmitting the secret itself, a breakthrough that made secure communication between parties with no prior relationship practical for the first time. Their paper also introduced the broader concept of a public-key cryptosystem, in which each party has a mathematically linked pair of keys, one that can be shared openly and one kept private, an idea that underlies most of the encryption and digital signature systems used to secure the modern internet. Diffie and Hellman jointly received the Turing Award in 2015 for their invention, honored specifically for fundamental contributions to modern cryptography.