BrydDes is a DOS program, which issues a known plaintext attack for DES encryption. The method is brute force. ECB mode and CBC mode with known IV are supported. On a Pentium 120, this version of the program can test 369,000 keys in a second. Please note that this is a beta-release. A new version will be shipped February 11th, or earlier if errors are discovered. So far source is not included. Automatic restart from the last key tested is not supported yet, but a shell could be written. The code is tested on a Pentium, but should run on a 486. The program is available at http://inet.uni-c.dk/~svolaf/des.htm Svend Olaf PS. "Bryd" is crack or break in Danish.