How are authentication codes used?

How are authentication codes used?

• A. A biometric scan is used to confirm identity
• B. A single-digit number is entered into a keypad to unlock the system
• C. Codes are exchanged verbally to verify identity
• D. A two-digit number is passed to the alarm custodian who passes a number back so that the two numbers add up to the code for the respective month

Answer: (D)

Authentication codes are used through dynamic, knowledge-based exchanges that prove you have access to the secret without simply transmitting it. In this scenario, a user and the alarm custodian perform a calculation: the user provides a number, the custodian returns another number, and together they add up to the current monthly code. This is a challenge–response style of authentication. It verifies that the user knows the secret and can perform the proper calculation, while the actual code stays protected and changes over time, making it harder to reuse or intercept. This approach is more secure and practical for code-based access than relying on a single digit or a verbal sharing of a code, and it goes beyond basic biometric verification which confirms identity through a physical trait rather than a shared code.

Authentication codes are used through dynamic, knowledge-based exchanges that prove you have access to the secret without simply transmitting it. In this scenario, a user and the alarm custodian perform a calculation: the user provides a number, the custodian returns another number, and together they add up to the current monthly code. This is a challenge–response style of authentication. It verifies that the user knows the secret and can perform the proper calculation, while the actual code stays protected and changes over time, making it harder to reuse or intercept.

This approach is more secure and practical for code-based access than relying on a single digit or a verbal sharing of a code, and it goes beyond basic biometric verification which confirms identity through a physical trait rather than a shared code.