vBulletin encrypted passwords

[Brad]

vBulletin does not encrypt passwords!

Encryption is the process of storing the orginal data in such a way that a cypher can later decrypt the information so it can be used in it's orignal form. Encryption is something that you would only use in a case where you needed to share certain information with a group of people without having that information getting to people outside of that group.

What vBulletin uses for passwords is called a hash function, which is nothing like encryption. You can not get the orginal data from something that was ran through a hash function. Instead you take new input from the user (the password) and run it through the hash function, then you attempt to match the output from the new user input with older user input that is stored in another location. If both hashes match then the user has provided the correct input and will be allowed to log-in, if not the input he provided is wrong and you deny his log-in.

You see encryption is rather useless when it comes to passwords because the user should already know his password.