Originally Posted By: ireckon
Of course, your third parties (e.g., bank computers) store passwords somewhere, but you have no control over that storage.


Okay, the following is super-nerdy and nitpicky, and may not be of interest to anyone.

Most systems don't store your password. They store a hash of your password instead. A hash function is supposed to be a mathematical "trap door" that takes an input, does math to it and comes out with a fixed-length output that's repeatable and unique to the input. That's impossible, so there are multiple inputs that can repeat the same output. That's called a hash collision.

Anyway, when you enter your password, the system authenticating you performs the same hash function on your input and compares the hash output to the hash output it has stored in your user record.