letter 'i' and the letter 'o', substitute all i's for 1's, substitute all o's for 0's, and append an = sign. These rules could also process the GECOS field in the password file, allowing the program to use the stored names of the users in addition to the existing word lists. Crack's dictionary generation rule syntax was subsequently borrowed and extended by Solar Designer for John the Ripper. The dictionary generation software for Crack was subsequently reused by Muffett to create CrackLib, a proactive password checking library that is bundled with Debian and Red Hat Enterprise Linux-derived Linux distributions. Network distributed password cracking As password cracking is inherently embarrassingly parallel Crack v4.0a introduced the ability to use a network of heterogeneous workstations connected by a shared filesystem as parts of a distributed password cracking effort. All that was required for this was to provide Crack with a configuration file containing the machine names, processing power rates and flags required to build Crack on those machines and call it with the -network option. See also Computer security Password cracking Aircrack-ng Cain and Abel DaveGrohl Hashcat John the Ripper L0phtCrack Ophcrack RainbowCrack References External links Password cracking - A quick guide to success crack Unix security-related software Password cracking software Linux security software