Whitfield Diffie and Martin Hellman are credited with the invention of public-key cryptography.

In 1976, Diffie and Hellman of Stanford University, California, submitted a paper New Directions in Cryptography to the IEEE (Institute of Electronic and Electrical Engineering), introducing their idea of public-key algorithms.

"New Directions in Cryptography." Whitfield Diffie and Martin Hellman. 'IEEE Transactions On Information Theory'. Volume IT-22 Number 6. (Periodical. USA.) November 1976.