DESCHALL Project

To search the 72 quadrillion possible keys of a 56-bit DES key using conventional computers was considered impractical even in the 1990s. Rocke Verser already had an efficient algorithm that ran on a standard PC and had the idea of involving the spare time on hundreds of other such machines that were connected to the internet. So they set up a server on a 486-based PS/2 PC with 56MB of memory and announced the project via Usenet towards the end of March. Client software was rapidly written for a large variety of home machines and eventually some more powerful 64 bit systems. There were two other main contenders: SoINET (a Swedish group), and a group at Silicon Graphics, a manufacturer of high-performance computers, which was in the lead until late in the day. Other groups using supercomputers withdrew after SYN flood attacks on their networks. ==The Project==

With the software that was used, a single 200 MHz Pentium system was able to test approximately 1 million keys/second if it was doing nothing else. At this rate it would take around 2,285 years to search the entire key-space. The number of computers being used rose rapidly and in the end, a total of 78,000 different IP addresses had been recorded, with a maximum of 14,000 unique hosts in a 24-hour period. By the time the key was found, they had searched about a quarter of the key-space and were searching about 7 billion keys per second, but the number of participants was still increasing rapidly. The solution was: Strong cryptography makes the world a safer place. The owner of the computer that found the solution was awarded $4,000 of the prize, with the rest going to the originator of the project. The conclusion of the paper describing the project was "We have demonstrated that a brute-force search of DES keyspace is not only possible, but is also becoming practical for even modestly funded groups. RSA's prize for the find was US$10,000; it is safe to say that DES is inadequate for protecting data of any greater value." ==See also==