Hashing with salt: With this technique, the hashes are randomized by appending or prepending a random string, called a “salt.” This is applied to the password before hashing.They are similar to lookup tables, except that they sacrifice hash cracking speed to make the lookup tables smaller. Rainbow tables: Rainbow tables are a time-memory technique.Reverse lookup tables: This attack allows for a cyber attacker to apply a dictionary or brute-force attack to many hashes at the same time without having to pre-compute a lookup table.Lookup tables: Hashes are pre-computed from a dictionary and then stored with their corresponding password into a lookup table structure.Other approaches used to crack passwords: It should be noted that there is no guaranteed way to prevent dictionary attacks or brute-force attacks. These techniques make use of a file that contains words, phrases, common passwords and other strings that are likely to be used as a viable password. Each attempt is hashed and then is compared to the actual hashed value to see if they are the same, but the process can take a long time.ĭictionary and brute-force attacks are the most common ways of guessing passwords. The simplest way to crack a hash is to try first to guess the password.