In 250 days and with the combined efforts of some 4,000 teams of computers, distributed.net has completed the RSA Data Security Challenge to break a 56-bit RC5 encryption algorithm, demonstrating that groups of networked computers can break such encryption. Team members participated by installing client software on their computers. The client software communicated with centralized servers over the Internet to perform the math necessary to break an encrypted message. Before locating the key needed to decrypt the message, the teams analyzed 47 percent of the possible keys, some 34 quadrillion sequences. The encrypted message read, "It's time to move to a longer key length." Although many Mac users participated, including the Apple Evangelistas team led by Guy Kawasaki, the key was broken by Peter Stuer's Intel-based PC. Peter was part of the STARLab Bovine Team, primarily located in Brussels, Belgium.

Distributed.net has begun a 64-bit challenge and a Macintosh client is available via FTP as a 303K download; look for it also on the distributed.net Web site shortly.

<ftp://ftp.distributed.net/pub/rc5-64/v2.6401/ rc56401-macos.sit.hqx>
<http://www.distributed.net/rc5/>

Future plans for distributed.net include updating the client software to version 3, which will be smart enough to query client hardware to determine which computational tasks suit it best. Future tasks besides breaking encryption codes may include doing computational work for SETI (Search for Extraterrestrial Intelligence) and participating in the Mersenne prime number search. According to David McNett at distributed.net, although 68040-based Macs provide little CPU power to breaking RSA's encryption challenges, they should prove more useful in locating new prime numbers. David noted the Macintosh in general and particularly PowerPC-based Macs made a "very stunning" contribution to meeting the 56-bit challenge.