Martin Hellman - Computer Privacy Debate

Computer Privacy Debate

Hellman has been a long-time contributor to the computer privacy debate. He and Diffie were the most prominent critics of the short key size of the Data Encryption Standard in 1975. An audio recording survives of their review of DES at Stanford in 1976 with Dennis Branstad of NBS and representatives of the National Security Agency. Their concern was well-founded: subsequent history has shown not only that NSA actively intervened with IBM and NBS to shorten the key size, but also that the short key size enabled exactly the kind of massively parallel key crackers that Hellman and Diffie sketched out, which when ultimately built outside the classified world, made it clear that DES was insecure and obsolete. In 2012, a $10,000 commercially available machine can recover a DES key in days. Hellman also served (1994–96) on the National Research Council's Committee to Study National Cryptographic Policy, whose main recommendations have since been implemented.