Technology Corner: Brute Force Password Generation -- Basic Iterative and Recursive Algorithms

Most information systems are secured at minimum by some form of password protection. For various reasons a password may be unavailable, requiring some form of password recovery procedure. One such procedure is software-based automated password recovery, where a program attempts to log into a system by repeatedly trying different password combinations. At the core of such software is a password generator. This article describes the basic iterative and recursive algorithms for generating all possible passwords of a given length, which is commonly referred to as brute-force password generation. The paper ends with a discussion of alternative password recovery procedures one should attempt before brute-force password recovery.