The brute-force attack is a very old type of attack on the user/password authentication where all kinds of character combinations are checked to guess a password. This is usually very time-consuming and triggers suspicious system behavior, which may be easily detected.

A more advanced type of the brute-force attack is the dictionary attack. Instead of checking all character strings, only a specific set of words from a dictionary is used for the attack. This may considerably reduce the time needed to crack a password, but it may also result in a password not being found.