IPA IP 2025 Question 100
A question IPA Japan published in 令和7年度 ITパスポート試験 公開問題 問100, translated into English. ITPEC is based on the same exams.
When the factors used for personal authentication are classified into the three (3) categories of knowledge, possession, and biometrics, which of the following is an example of authentication that uses possession as the factor?
Explanation
Authentication using SMS — a code sent by SMS proves that the user holds the registered mobile phone, a thing the user has.
The three factors of authentication:
- •Knowledge (something you know): password, PIN, the answer to a secret question
- •Possession (something you have): IC card, hardware token, the phone that receives an SMS code or runs an authenticator app
- •Biometrics (something you are): fingerprint, vein, iris, face, and behavioural traits such as a signature's strokes
In SMS authentication only the person holding the phone registered to the number receives the one-time code, so it rests on possession.
Answer (a)
Why not others:
- •(b) — the iris is a physical characteristic of the body: biometrics
- •(c) — handwriting, pen pressure and writing speed are behavioural characteristics, also biometrics
- •(d) — a pre-set question and its answer are something the person knows: knowledge
Key rule: Know (password, secret answer), have (card, token, phone for SMS), are (fingerprint, iris, signature dynamics); multi-factor authentication combines two different kinds.
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.