An access code is another name for a password that is used to provide some security against unauthorized access to data on a computer. Depending on the rules determined by the system administrator for a user-created access code, it can be alphanumeric, case-sensitive and/or contain symbols. Sometimes an access code has to contain a minimum number of characters and is limited to a maximum number of characters. Password authentication takes place after a person enters a password into the correct field of a form and presses the "enter" key or clicks on a button or hyperlink called something such as "sign in" or "login." The behind-the scenes process entails verification of the entered code against the code that is stored in a database.
The authentication process, especially for entering protected web pages, generally not only involves verifying the access code entered into the form field against the code that is stored in the database, it also involves checking that it matches with a unique username. If either the username or the password entered is incorrect, most systems are programmed to deny entry and display an error message to the user. Error messages, for security reasons, rarely reveal whether the problem is specifically with the username, the password or both. An access code can be user-generated or dynamically generated. It also can be classified as weak, moderately strong or strong.
It generally is not a good idea for an access code to be the name of a person, place or thing, such as the name of a friend, a city or a pet, because when only letters are used for passwords, they can be more easily cracked or discovered. An access code that is considered moderately strong or strong is one that is at least eight characters in length and contains uppercase and lowercase letters as well as numbers and symbols. Such a strategy makes it much more difficult to discover the password and is almost always preferred, particularly for very sensitive data.
Gaining access to a user account with a website, to a student account at a college or university and to an email account are just some examples of when an access code is needed. The use of an automated teller machine (ATM) and a debit card also require a secret code, in which case it is usually referred to as a personal identification number (PIN). Even the retrieval of voicemail messages from a cellular phone typically requires the entry of an access code. Although an ATM, debit card or cellular phone are not considered to be computers themselves, they either connect to a computer or they use artificial intelligence. Sometimes people also choose to use a password to protect their data stored on a universal serial bus (USB) drive so that their files have at least some security in the event that the drive is temporarily misplaced or stolen.