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Cracking DES: Secrets of
Encryption Research, Wiretap Politics & Chip Design - How Federal
Agencies Subvert Privacy

July 17, 1998




SAN FRANCISCO, CA -- The Electronic Frontier Foundation (EFF) today raised the level of honesty in crypto politics by revealing that the Data Encryption Standard (DES) is insecure. The U.S. government has long pressed industry to limit encryption to DES (and even weaker forms), without revealing how easy it is to crack. Continued adherence to this policy would put critical infrastructures at risk; society should choose a different course.

To prove the insecurity of DES, EFF built the first unclassified hardware for cracking messages encoded with it. On Wednesday of this week the EFF DES Cracker, which was built for less than $250,000, easily won RSA Laboratory's "DES Challenge II" contest and a $10,000 cash prize. It took the machine less than 3 days to complete the challenge, shattering the previous record of 39 days set by a massive network of tens of thousands of computers. The research results are fully documented in a book published this week by EFF and O'Reilly and Associates, entitled "Cracking DES: Secrets of Encryption Research, Wiretap Politics, and Chip Design."

"Producing a workable policy for encryption has proven a very hard political challenge. We believe that it will only be possible to craft good policies if all the players are honest with one another and the public," said John Gilmore, EFF co-founder and project leader. "When the government won't reveal relevant facts, the private sector must independently conduct the research and publish the results so that we can all see the social trade-offs involved in policy choices."

The nonprofit foundation designed and built the EFF DES Cracker to counter the claim made by U.S. government officials that governments cannot decrypt information when protected by DES, or that it would take multimillion-dollar networks of computers months to decrypt one message. "The government has used that claim to justify policies of weak encryption and 'key recovery,' which erode privacy and security in the digital age," said EFF Executive Director Barry Steinhardt. It is now time for an honest and fully informed debate, which we believe will lead to a reversal of these policies."

"EFF has proved what has been argued by scientists for twenty years, that DES can be cracked quickly and inexpensively," said Gilmore. "Now that the public knows, it will not be fooled into buying products that promise real privacy but only deliver DES. This will prevent manufacturers from buckling under government pressure to 'dumb down' their products, since such products will no longer sell." Steinhardt added, "If a small nonprofit can crack DES, your competitors can too. Five years from now some teenager may well build a DES Cracker as her high school science fair project."

The Data Encryption Standard, adopted as a federal standard in 1977 to protect unclassified communications and data, was designed by IBM and modified by the National Security Agency. It uses 56-bit keys, meaning a user must employ precisely the right combination of 56 1s and 0s to decode information correctly. DES accounted for more than $125 million annually in software and hardware sales, according to a 1993 article in "Federal Computer Week." Trusted Information Systems reported last December that DES can be found in 281 foreign and 466 domestic encryption products, which accounts for between a third and half of the market.

A DES cracker is a machine that can read information encrypted with DES by finding the key that was used to encrypt that data. DES crackers have been researched by scientists and speculated about in the popular literature on cryptography since the 1970s. The design of the EFF DES Cracker consists of an ordinary personal computer connected to a large array of custom chips. It took EFF less than one year to build and cost less than $250,000.

This week marks the first public test of the EFF DES Cracker, which won the latest DES-cracking speed competition sponsored by RSA Laboratories ( http://www.rsa.com/rsalabs/ ). Two previous RSA challenges proved that massive collections of computers coordinated over the Internet could successfully crack DES. Beginning Monday morning, the EFF DES Cracker began searching for the correct answer to this latest challenge, the RSA DES Challenge II-2. In less than 3 days of searching, the EFF DES Cracker found the correct key. "We searched more than 88 billion keys every second, for 56 hours, before we found the right 56-bit key to decrypt the answer to the RSA challenge, which was 'It's time for those 128-, 192-, and 256-bit keys,'" said Gilmore.

Many of the world's top cryptographers agree that the EFF DES Cracker represents a fundamental breakthrough in how we evaluate computer security and the public policies that control its use. "With the advent of the EFF DES Cracker machine, the game changes forever," said Whitfield Diffie, Distinguished Engineer at Sun Microsystems and famed co-inventor of public key cryptography. "Vast Internet collaborations cannot be concealed and so they cannot be used to attack real, secret messages. The EFF DES Cracker shows that it is easy to build search engines that can."

"The news is not that a DES cracker can be built; we've known that for years," said Bruce Schneier, the President of Counterpane Systems. "The news is that it can be built cheaply using off-the-shelf technology and minimal engineering, even though the department of Justice and the FBI have been denying that this was possible." Matt Blaze, a cryptographer at AT&T Labs, agreed: "Today's announcement is significant because it unambiguously demonstrates that DES is vulnerable, even to attackers with relatively modest resources. The existence of the EFF DES Cracker proves that the threat of "brute force" DES key search is a reality. Although the cryptographic community has understood for years that DES keys are much too small, DES-based systems are still being designed and used today. Today's announcement should dissuade anyone from using DES."

EFF and O'Reilly and Associates have published a book about the EFF DES Cracker, "Cracking DES: Secrets of Encryption Research, Wiretap Politics, and Chip Design." The book contains the complete design details for the EFF DES Cracker chips, boards, and software. This provides other researchers with the necessary data to fully reproduce, validate, and/or improve on EFF's research, an important step in the scientific method. The book is only available on paper because U.S. export controls on encryption potentially make it a crime to publish such information on the Internet.

EFF has prepared a background document on the EFF DES Cracker, which includes the foreword by Whitfield Diffie to "Cracking DES." (See http://www.eff.org/descracker/ ). The book can be ordered for worldwide delivery from O'Reilly & Associates via the Web ( http://www.ora.com/catalog/crackdes ), or phone (1 800 998 9938, or +1 707 829 0515.)

The Electronic Frontier Foundation is one of the leading civil liberties organizations devoted to ensuring that the Internet remains the world's first truly global vehicle for free speech, and that the privacy and security of all on-line communication is preserved. Founded in 1990 as a nonprofit, public interest organization, EFF is based in San Francisco, California. EFF maintains an extensive archive of information on encryption policy, privacy, and free speech at the EFF Web site ( http://www.eff.org ).

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