Some websites allow users to associate a second form of authentication with their accounts, such as a password or PIN number, thereby requiring both the user's password and a second factor in order to log in. Two-factor authentication can further help to reduce the ease of guessing passwords. While a wordlist provides some defence against attack by guessing the password, it is vulnerable. Wordlists are a common way to create a single password that meets the required criteria for each site. They also address issues such as password reuse, which causes a compromise of one account to give an attacker access to related accounts.

For example, if a password must contain two uppercase letters, a lowercase letter, and one digit, and the strongest password an attacker can guess is three digits, an attacker attempting to guess the first digit (the most important guess) will likely fail or not even try. If an attacker is unable to guess the first attempt at a password, it may be impossible to guess the password. While it is possible to reduce the difficulty of guessing the initial password, the complexity of the initial random password will be increased. This is the method used by most services that require passwords, such as websites that allow logins and online banking. For an initial password, users can be required to choose a unique password for each new account or site.

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