Password recovery refers to an attempt to crack a lost or forgotten password in order to be able to login to an account or system. The attempts of password recovery may be used by malicious hackers as well as righteous individuals who want to legitimately login to their account, but are unable to do so because they forgot the account password.
Password recovery tools can make use of the following strategies: guessing, brute force attack, pre-computation and use of password recovery software. Guessing can be done either by humans or special cracking programs which use one or several dictionaries to guess meaningful words. According to the statistics, almost 4% of all passwords are a single word found in a dictionary, which makes it possible to easily hack those passwords by a simple guessing method.
The brute force attack is an attempt to crack a password by trying all possible digit-letter-symbol variations according to the rules of password creation which are widely known to the public. In theory, this method will always be successful, but in reality it is not that easy to crack a lengthy password using the brute force attack. However, with shorter passwords, it can be effectively used. The major problem with the brute force attack method is that the login attempts are often logged, and after a few failures to enter a valid password, the account may be blocked.
The pre-computation method is an attempt to decrypt the password using a known encryption algorithm. Pre-computation can be effective, if the encryption algorithm is known to the hacker. However, it is still relatively inefficient with long passwords. The more advanced methods of pre-computation are time-memory tradeoff and memoization which allow cracking a long password faster and are generally more efficient.
The use of password recovery software can be the last resort in any lost or forgotten password episode. However, for the passwords to be recovered, it is required that it be stored somewhere. It is advisable to store your passwords in a protected database as opposed to storing it in a file, or browser, or even on a piece of paper. The password manager software allows recovering your password from a password database, if you forget your password and are unable to login to the system.