outer@utcsrgv.UUCP (Richard Outerbridge) (10/25/83)
DATA PRODUCT NEWS, September/October 1983 p22 "Profs bust security system" "Two University of Waterloo mathematics professors, an electrical engineering professor and a former student, have made a surprising discovery: one of the most sophisticated computer security devices can be broken. "The security device is the Public Key Distribution System (PKDS) often used in conjunction with the most common encryption (coding) devices available - the Data Encryption Standard (DES). "...... "It was generally felt it would take thousands of computer years to figure out the key from two elements of the Galois field 2^127 because of its complexity. But the Waterloo mathematicians can do it in a matter of minutes on a high speed machine. "They say it's possible because for a given relatively small collection of special field elements they can figure out the keys. Once the database has been computed it is relatively easy to calculate any other key. "However, the security technique isn't a complete failure. [Using a Galois field substantially larger than 2^127 would increase the work factor so much that....] A PKDS based on a field of this size .... would be very difficult if not impossible to break." At least using their technique. And so another one bites the dust. utcsrgv!outer @ U of Toronto CSRG