IPA IP 2026 Question 80
A question IPA Japan published in 令和8年度 ITパスポート試験 公開問題 問80, translated into English. ITPEC is based on the same exams.
Which of the following is the appropriate combination of words to be inserted into blanks A and B in the description below concerning biometric authentication?
When starting the design of a system that uses biometric authentication, it is necessary to clarify the purpose of the system and the use of the authentication, and to formulate a policy for setting the authentication accuracy. It can be said that when the false acceptance rate is set to be A, the authentication emphasizes security, and when the false rejection rate is set to be B, the authentication emphasizes convenience for the genuine person.
Explanation
A: low, B: low — a low false acceptance rate favours security, and a low false rejection rate favours the genuine person’s convenience.
- •False acceptance rate: the probability that another person is wrongly accepted. Setting it low makes impersonation harder, so the authentication emphasizes security
- •False rejection rate: the probability that the genuine person is wrongly rejected. Setting it low spares the user repeated attempts, so the authentication emphasizes convenience
The two trade off: a stricter matching threshold lowers the false acceptance rate but raises the false rejection rate, and a looser one does the opposite. That is why the design starts from the system’s purpose: entry to a data centre may accept more false rejections to keep false acceptance low, while unlocking a phone may favour fewer rejections.
Answer (d)
Why not others:
- •(a) — a high false acceptance rate lets impostors in, the opposite of security, and a high false rejection rate keeps rejecting the user, the opposite of convenience
- •(b) — a low false rejection rate is right, but a high false acceptance rate weakens security
- •(c) — a low false acceptance rate is right, but a high false rejection rate rejects the genuine person more often, which hurts convenience
Key rule: Lowering the false acceptance rate makes authentication more secure, lowering the false rejection rate makes it more convenient, and tightening one loosens the other.
Security · AI-written, may contain errors
This question comes from the past questions IPA Japan publishes, translated into English by ITPEC Practice. ITPEC Practice is an independent study tool and is not affiliated with IPA or ITPEC. See the original paper (PDF) or Report an issue.