How are authentication codes used?

How are authentication codes used?

• A. A biometric scan authenticates identity
• B. A single-digit code is entered into a keypad to unlock the system
• C. Codes are exchanged verbally over radio 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 use a challenge‑response style to prove you know a shared rule or secret without simply sending that secret itself. In this example, the caller provides a two‑digit number and the alarm custodian responds with another number. When you add those two numbers together, you get the code for the current month. This dynamic relationship means the verification depends on both sides and on the current month code, so identity is confirmed through the computed result rather than by transmitting a static password. This demonstrates why such a method is useful: it prevents just replaying a single static code and relies on a real‑time calculation that both parties can verify. The other approaches described don’t capture that same verification method. A biometric scan confirms who you are but not a numeric code exchange; a single‑digit static code is easier to guess or reuse; and verbally exchanging codes over radio can be intercepted or spoofed without a built‑in verification rule. The summed two‑number approach is a practical example of how authentication codes can be used to verify identity in a secure, dynamic way.

Authentication codes use a challenge‑response style to prove you know a shared rule or secret without simply sending that secret itself. In this example, the caller provides a two‑digit number and the alarm custodian responds with another number. When you add those two numbers together, you get the code for the current month. This dynamic relationship means the verification depends on both sides and on the current month code, so identity is confirmed through the computed result rather than by transmitting a static password.

This demonstrates why such a method is useful: it prevents just replaying a single static code and relies on a real‑time calculation that both parties can verify. The other approaches described don’t capture that same verification method. A biometric scan confirms who you are but not a numeric code exchange; a single‑digit static code is easier to guess or reuse; and verbally exchanging codes over radio can be intercepted or spoofed without a built‑in verification rule. The summed two‑number approach is a practical example of how authentication codes can be used to verify identity in a secure, dynamic way.