One of most widely used forms of attack. It tries using every possible code, combination, or password until it finds the one that works. Some methods used to circumvent a brute force attack: 1) imposing a delay between failed attempts 2) locking the account after so many failed attempts and 3) requiring that two or three issued words, be typed back by you, to prove you are a person and not a computer, and 4) when you sign up for the account you answer 2-3 random questions. You can then be challenged to give the correct answer to one of the questions before you can proceed.