Paul Kocher, the machine's principal designer, displays one of the boards holding 64 custom search microchips. The six cabinets (behind) house 29 boards whose searching is coordinated by a PC.

The machine, shown here running, tests over 90 billion keys per second, taking an average of less than 5 days to discover a DES key.

Over 1800 of these custom microchips, built by AWT, perform the DES key search. Each chip contains 24 search units that test possible keys against dual ciphertexts.