How to crack passwords

• Xeon 500Mhz 2MB cache does 20000 crypts/sec/CPU

• There are lots of possible passwords, but many people don't take advantage of the 95 different characters and 8 character length

• Brute force attacks (100 CPUx1week = 16800 CPU hours):

• 5 char keyspace can be exhausted in 107 CPU hours (95^5/20000x3600)

• 6 char passwords ([A-Za-z0-9]{6}) in 788 CPU hours (62^6/20000x3600)

• 7 char passwords ([A-Za-z][a-z0-9]{6}) in 1572 CPU hours (52x36^6/20000x3600)

• 8 char passwords ([a-z]{6}[a-z0-9]{2}) in 5560 CPU hours (26^6*36^2/20000x3600)

• 8 char keyspace in 92141726 CPU hours or 10511 CPU year (95^8/20000x3600)

• $250K hardware DES cracker

• http://www.cryptography.com/des/despictures/index.html

• 90 billion keys per second Ô 8 char keyspace in 20 hours