Crypto pioneers Diffie and Hellman win Nobel Prize of Computing

ACM, the Association for Computing Machinery has announced at RSA Conference that it has awarded crypto pioneers Whitfield Diffie and Martin E. Hellman the 2015 ACM A.M. Turing Award for critical contributions to modern cryptography.

The ACM Turing Award, often referred to as the “Nobel Prize of Computing,” carries a $1 million prize with financial support provided by Google. Diffie, former Chief Security Officer of Sun Microsystems and Hellman, Professor Emeritus of Electrical Engineering at Stanford University, will receive the award and the prize this summer at AMC’s annual Awards Banquet.

The ability for two parties to communicate privately over a secure channel is fundamental for billions of people around the world. On a daily basis, individuals establish secure online connections with banks, e-commerce sites, email servers and the cloud.

Diffie and Hellman’s groundbreaking 1976 paper, “New Directions in Cryptography,” introduced the ideas of public-key cryptography and digital signatures, which are the foundation for most regularly-used security protocols on the Internet today. The Diffie-Hellman Protocol protects daily Internet communications and trillions of dollars in financial transactions.

“Naturally I’m thrilled by this by this award, but thrilled for cryptography,” Diffie said. “It’s the third time the Turing award has been given to cryptographers. The fact that it is so central to the field is amazing.”

In the past, when two parties were seeking to establish secure communications, they needed to have identical keys. Supplying these keys—key management—was a major limitation of the flexibility of encrypted communications.

Two significant shortcomings of symmetric cryptosystems are the need for a secure means of key transfer and, because both parties have the same key, one could forge a message to oneself, claiming it came from the other. In addition, overuse of a particular key may provide an opponent with sufficient ciphertext to break the cryptosystem (i.e., discover the key).

In “New Directions in Cryptography,” Diffie and Hellman presented an algorithm that showed that asymmetric or public-key cryptography was possible. In Diffie and Hellman’s invention, a public key, which is not secret and can be freely distributed, is used for encryption, while a private key, that need never leave the receiving device, is used for decryption. This asymmetric cryptosystem is designed in such a way that the calculation of the private key from the public key is not feasible computationally, even though one uniquely determines the other.

Reversing the process provides a digital signature. The transmitter of a message uses a private key to sign the message, while the receiver uses the transmitter’s public key to authenticate it. Such digital signatures are more secure than written signatures because changing even one word of the message invalidates the signature. In contrast, a person’s written signature looks the same on a $10 check and a $1,000,000 check.

In addition to laying the foundation for today’s online security industry and establishing cryptography as a leading discipline within computer science, Diffie and Hellman’s work made encryption technologies accessible to individuals and companies, instead of just the government.

“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,” said ACM President Alexander L. Wolf. “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.”

The announcement of the prize comes at a time when encryption and encryption backdoors are being heavily debated by around the world, but most prominently in the US.

RSA Conference 2016

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