In a typical office, biometric authentication might be used to control access to employees and registered visitors only. We know the system will have some false negatives, some employees falsely denied access, so we need a human override, someone who can examine the employee and allow access in spite of the failed authentication. Thus, we need a human guard at the door to handle problems as well as the authentication device; without biometrics, we would have had just the guard. Consequently, we have the same number of personnel with or without biometrics, plus we have the added cost to acquire and maintain the biometrics system. Explain the security advantage in this situation that justifies the extra expense.

What will be an ideal response?

By automating the vast majority of authentications, the guard can better scrutinize the few that require manual intervention, and the guard’s choices can be audited more easily. Also, the guard’s newly acquired downtime can be spent on new security tasks.