問80
頻出度★★★
バイオメトリクス認証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を利用したシステムの設計を始めるときには, システムの目的と認証の用途を明らかにし, 認証精度の設定方針を策定することが必要である。 他人受入率が a なるように設定した場合は, 安全性を重視した認証になり, 本人拒否率が b なるように設定した場合は, 本人の利便性を重視した認証になるといえる。
令和8年度 ITパスポート試験 問80
This question's explanation and your answers so far.
解説
問 80
Incorrectア
a＝high is wrong. Setting the False Acceptance Rate high increases the proportion of cases where others are mistaken for the genuine user, which permits unauthorized intrusion and lowers security, so it does not result in a security-focused setting.
Incorrectイ
a＝high is wrong. Setting the False Acceptance Rate high lowers security, so it does not result in security-focused authentication (b＝low is valid as a convenience-focused setting).
Incorrectウ
b＝high is wrong. Setting the False Rejection Rate high increases the proportion of cases where the legitimate genuine user is rejected, worsening usability, so it does not result in convenience-focused authentication.
- エ
正解 The False Acceptance Rate (FAR) is the proportion of cases where others are mistakenly accepted as the genuine user. Setting it low makes unauthorized intrusion less likely, so the authentication emphasizes security (a＝low). The False Rejection Rate (FRR) is the proportion of cases where the genuine user is mistakenly rejected. Setting it low makes legitimate users less likely to be turned away, so the authentication emphasizes the user's convenience (b＝low). Therefore the combination a＝low and b＝low is correct, and the answer is エ.
ここがポイント
- False Acceptance Rate (FAR) ＝ the proportion of mistakenly accepting others. The lower it is set, the higher the security.
- False Rejection Rate (FRR) ＝ the proportion of mistakenly rejecting the genuine user. The lower it is set, the higher the convenience. The two are in a trade-off relationship.
用語