Another one-time password technique uses a challenge/response approach to achieve the same end. When the user attempts to log on, the network authentication software issues a six-character code (the challenge) that the card can either scan optically or it can be entered into the card via its built-in keypad. The card’s internal algorithm then generates a one-time password (the response) that the user enters through the keyboard of the remote terminal. If the firewall recognizes the current password, access is permitted.