In this paper, the author examines brute force UNIX password cracking from the perspective of what resources a non-professional cracker could reasonably be expected to have. Estimations are made of cracker capabilities, and the strength of various passwords to resist attacks. In this day of password sniffers and TCP-hijack attacks, password cracking may seem passe', but given the continued growth in machines' speed and interconnectedness, brute force cracking deserves another look. The encryption is further permuted by the addition of a 12-bit random 'salt'. If a match is found, the password is known.
Cryptographers find better algorithms and optimizations.
Machines are being networked together, allowing easy parallelization of the guessing process. All of these taken together means that the casual cracker now has resources at his disposal that would be the envy of researchers a mere five years ago - yet the basic UNIX password algorithm has not changed in over 20 years. As might be suspected, this is a hazardous situation. Easier in this case means faster. With a single salt, each word in a guess list only needs to be encrypted once.