Advantages of Password Authentication

By John Papiewski

Password authentication systems lock out all but legitimate users.
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When you log into a computer with a username and password, you are using password authentication, a reliable method for identifying users. You can share your username with others, although the password remains a secret, as it uniquely identifies you to the computer. Password authentication provides a reasonable level of security at a low cost. Alternatives include biometrics, such as a fingerprint scanner; challenge/response where the computer prompts you for more information; and hardware, such as a keycard.

Easy Implementation

Password authentication systems exist in software. To create them, a programmer creates an input form consisting of two text fields, one standard and one obscured. The standard field accepts the username and the obscured field accepts the password. As the user types in a password, the obscured field responds to each character with an asterisk; this prevents another person from seeing the password over her shoulder. The HTML used to create Web pages includes a convenient obscured password field, as does Microsoft's Access database and other types of screen input software.

Low Cost

Because software handles password authentication, the only cost comes from the minor effort required for programming. A single authentication program can support any number of users. Unlike keycard and biometric authentication methods, the computer requires no additional hardware expenses to make password authentication work.

Easy to Change

Most password authentication systems let you change your password as often as you want; you log in with your existing user ID and password, and then update the password in your user settings. Biometric authentication systems cannot change; they are fixed to your fingerprints, retinas or other body feature. If you lose an access card or USB stick to a hardware-based system, you can possibly get it replaced, although not as easily as changing a password.

Widely Used

Password authentication is familiar to nearly all computer users; once you've learned how to log in to one system, you can apply the same method to others. Software developers don't need to invent new kinds of authentication each time they create a new app or website, they use the same process already found in existing systems. The benefits of familiarity extend to administrators responsible for setting up and maintaining user security; the same general practices apply to all systems using password authentication. By comparison, hardware and biometric authentication systems are less common and require more training.


Logging in with a user ID and password is straightforward; if they match the data stored in the computer's security database, the program authenticates them and gives them access. Biometric systems are less reliable; a fingerprint sensor may misread your finger and keep you locked out of the computer. Injuries or other changes to the affected body part will affect reliability of the authentication system, as will problems with the sensor.