Olympics Of Information Scrambling -- NIST Announces Encryption Standard Finalists

Secretary of Commerce William Daley hailed today's announcementas a significant step toward creating a more secure digitaleconomy.

"This is a critical milestone in developing the AdvancedEncryption Standard. The AES will serve as an important securitytool in support of the dynamic growth of electronic commerce,"Daley said.

A year ago, researchers from 12 different countries submitted 15candidates for the AES--the new encoding method that eventuallywill be adopted by the federal government. Since that time,cryptographers have tried to find ways to "attack" the differentencoding methods, looking for weaknesses that would compromisethe encrypted information. Today's decision narrows the field ofcontenders from 15 candidates to only five.

The five finalists are sophisticated mathematical formulas,called algorithms, which are at the heart of computerizedencryption systems. Encryption systems encode everything fromelectronic mail to the secret personal identification numbers, orPINs, that people use with bank teller machines.

The AES will be a public algorithm designed to protect sensitivegovernment information well into the next century. It willreplace the aging Data Encryption Standard, which NIST adopted in1977 as a Federal Information Processing Standard used by federalagencies to encrypt information. DES is used widely in theprivate sector as well, especially in the financial servicesindustry.

NIST's Information Technology Laboratory chose the following fivecontenders as finalists for the AES:

* MARS--developed by International Business Machines Corp. ofArmonk, N.Y.;

* RC6--developed by RSA Laboratories of Bedford, Mass.;

* Rijndael--developed by Joan Daemen and Vincent Rijmen of Belgium;

* Serpent--developed by Ross Anderson, Eli Biham and Lars Knudsen ofthe United Kingdom, Israel and Norway respectively; and

* Twofish--developed by Bruce Schneier, John Kelsey, Doug Whiting,David Wagner, Chris Hall and Niels Ferguson. (Many members ofthis group are associated with Counterpane Systems ofMinneapolis).

No significant security vulnerabilities were found for the fivefinalists during the initial analysis of the algorithms, and eachcandidate offers technology that is potentially superior for theprotection of sensitive information well into the 21st century.

NIST requested proposals for the AES on Sept. 12, 1997. Each ofthe candidate algorithms supports cryptographic key sizes of 128,192 and 256 bits. At a 128 bit key size, there are approximately340,000,000,000,000,000,000,000,000,000,000,000,000 (340 followedby 36 zeroes) possible keys.

The global cryptographic community has been helping NIST in theAES development process by studying the candidates. NIST usedfeedback from these analyses and its own assessments to selectthe finalists. The studies evaluated security and how fast thealgorithms could encrypt and decrypt information. The algorithmswere tested on everything from large computers to smart cards.

During the evaluation process NIST considered all comments,papers, verbal comments at conferences, reports and proposedmodifications, and its own test data. Each candidate algorithmwas discussed relative to the announced evaluation criteria andother pertinent criteria suggested during the public analysis. Adetailed report on the process, "Status Report on the First Roundof the Development of the Advanced Encryption Standard," isavailable on the AES web site at www.nist.gov/aes.

NIST is making the five finalists available for intensified studyand analysis by cryptographers, the public, industry andacademia. Analysis of the finalists will be presented at aconference in April 2000. NIST is accepting comments on thecandidates through May 15, 2000. Then it will review the commentsand draft the proposed AES (incorporating one or more of thealgorithms) for public comment. If all goes as planned, thestandard should be completed by the summer of 2001.

As a non-regulatory agency of the U.S. Department of Commerce'sTechnology Administration, NIST strengthens the U.S. economy andimproves the quality of life by working with industry to developand apply technology, measurements and standards through fourpartnerships: the Measurement and Standards Laboratories, theAdvanced Technology Program, the Manufacturing ExtensionPartnership and the Baldrige National Quality Program.