On Tuesday, the Association for Computing Machinery, the nation’s leading organization for computer science, awarded its annual top prize of $1 million to two men whose name will forever be immortalized in cryptography: Whitfield Diffie and Martin Hellman.

The 2015 ACM Turing Award, which is sometimes referred to as the "Nobel Prize of Computing," was awarded to a former chief security officer at Sun Microsystems and a professor at Stanford University, respectively.

In their landmark 1976 paper , the Diffie-Hellman key exchange was the first to explore ideas of " public-key cryptography ." That concept underpins much of modern cryptography, including PGP encrypted e-mail, TLS, and more. Public-key cryptography, also known as asymmetric cryptography, relies on two keys, one a freely shareable public key, the other a secret private key, thus eliminating the historic key management problem of the same key being kept by both the recipient and sender.

"Today, the subject of encryption dominates the media, is viewed as a matter of national security, impacts government-private sector relations, and attracts billions of dollars in research and development," Alexander L. Wolf, ACM's president, said in a statement . "In 1976, Diffie and Hellman imagined a future where people would regularly communicate through electronic networks and be vulnerable to having their communications stolen or altered. Now, after nearly 40 years, we see that their forecasts were remarkably prescient."

Prior to Diffie-Hellman, both the sender and the recipient of an encrypted message had to use the same key. If that key was stolen or otherwise compromised, every message sent using the key could be read. With asymmetric cryptography, anyone can send a message encrypted using the public key. Only the recipient's private key needs to be kept secure.

Coincidentally, the ACM announced the award the same day that FBI Director James Comey appeared before a congressional committee to discuss how encryption is a thorn in law enforcement’s side.