CISSP False Rejection Rate (FRR) Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Lower the sensitivity threshold [correct]

  Why this is correct

  Lowering the sensitivity threshold in a biometric system makes the matching algorithm less strict, requiring a lower degree of similarity between the live biometric sample and the enrolled template for a successful match. This adjustment increases the likelihood that variations in a legitimate user's presentation (e.g., slight angle changes, minor injuries) will still be accepted. Consequently, it directly reduces the False Rejection Rate (FRR), meaning fewer authorized individuals are incorrectly denied access, though it typically comes at the cost of increasing the False Acceptance Rate (FAR).

• ✗

  Increase enrollment sample quality

  Why it's wrong here

  Increasing the quality of enrollment samples, such as capturing multiple clear images or recordings under optimal conditions, generally improves the robustness and accuracy of the stored biometric template. A high-quality template can lead to better overall system performance by providing a more reliable baseline for future comparisons. While this can indirectly reduce both False Acceptance Rate (FAR) and False Rejection Rate (FRR) by making the system more accurate, it is not a direct or primary mechanism specifically for *minimizing* FRR without potentially impacting FAR. It aims for general accuracy, not a specific bias towards FRR reduction.

• ✗

  Use liveness detection

  Why it's wrong here

  Liveness detection, also known as anti-spoofing, is a crucial security feature designed to verify that the biometric sample presented is from a living person and not a synthetic artifact or a recorded presentation attack. While essential for preventing unauthorized access via spoofing, this technology operates independently of the core matching algorithm that compares a live sample to an enrolled template. Consequently, liveness detection does not directly influence the False Rejection Rate (FRR), which quantifies the rate at which legitimate users are incorrectly denied access.

• ✗

  Store templates securely

  Why it's wrong here

  Storing biometric templates securely is a critical security control to protect the confidentiality and integrity of sensitive user data from unauthorized access or compromise. However, the method of template storage, whether encrypted or in a a secure database, does not directly influence the operational parameters of the biometric matching algorithm itself. Therefore, it has no impact on the system's False Rejection Rate (FRR), which is a measure of legitimate users being denied access due to a mismatch.

Go deeper

Related to this question