Password length parameter

Short description: Basic parameter the value of which affects password strength against brute force attack

In telecommunication, a password length parameter is a basic parameter the value of which affects password strength against brute force attack and so is a contributor to computer security.

One use of the password length parameters is in the expression [math]\displaystyle{ P = L\times R /S }[/math], where [math]\displaystyle{ P }[/math] is the probability that a password can be guessed in its lifetime, [math]\displaystyle{ L }[/math] is the maximum lifetime a password can be used to log into a system, [math]\displaystyle{ R }[/math] is the number of guesses per unit of time, and [math]\displaystyle{ S }[/math] is the number of unique algorithm-generated passwords (the 'password space').

The degree of password security is determined by the probability that a password can be guessed in its lifetime.

See also

• Key stretching
• Password cracking