問69
頻出度★★★
バイオメトリクス認証における認証精度に関する次の記述中の a, b に入れる字句の適切な組合せはどれか。 バイオメトリクス認証において, 誤って本人を拒否する確率を本人拒否率といい, 誤って他人を受け入れる確率を他人受入率という。また, 認証の装置又はアルゴリズムが生体情報を認識できない割合を未対応率という。 認証精度の設定において, [ a ] が低くなるように設定すると利便性が高まり, [ b ] が低くなるように設定すると安全性が高まる。
令和3年度 ITパスポート試験 問69
This question's explanation and your answers so far.
解説
問 69
Incorrectア
a and b are swapped. Lowering a=False Acceptance Rate increases security, not convenience, and lowering b=False Rejection Rate increases convenience, not security. The correspondences convenience↔False Rejection Rate and security↔False Acceptance Rate have been interchanged, so it is wrong.
Incorrectイ
a=False Acceptance Rate is wrong. Lowering the False Acceptance Rate increases security, not convenience. Also, b=Failure to Recognize Rate is wrong; the Failure to Recognize Rate is an indicator of the rate at which the biometric information itself cannot be recognized, and it is not the security setting that governs whether others are accepted.
- ウ
正解 Convenience and security are determined by a trade-off over which of the two error rates that set the recognition accuracy you prioritize. First, for a, a state of high convenience means that “the legitimate person can pass smoothly.” If you set the False Rejection Rate (FRR)—the rate at which the legitimate person is mistakenly rejected—to be low, the person is less likely to be turned away, so convenience increases. Therefore a=False Rejection Rate. Next, for b, a state of high security means that “others are not let through.” If you set the False Acceptance Rate (FAR)—the rate at which others are mistakenly accepted—to be low, impersonation becomes harder to get through, so security increases. Therefore b=False Acceptance Rate. Thus a=False Rejection Rate, b=False Acceptance Rate, and the correct answer is ウ.
Incorrectエ
a=Failure to Recognize Rate is wrong. The Failure to Recognize Rate is the rate at which the device or algorithm cannot recognize biometric information, and it is not an indicator that directly expresses the convenience trade-off of whether the legitimate person can pass smoothly. b=False Rejection Rate is also wrong; the False Rejection Rate is an indicator related to convenience, not the security setting that increases by keeping others out.
ここがポイント
- The False Rejection Rate (FRR) and the False Acceptance Rate (FAR) are in a trade-off relationship: lowering the False Rejection Rate increases convenience, while lowering the False Acceptance Rate increases security.
- The Failure to Recognize Rate is a separate indicator showing the rate at which biometric information cannot be recognized, and it does not directly correspond to the trade-off of either convenience or security.
用語