問93
頻出度★★★
シングルサインオンの説明として, 適切なものはどれか。
平成28年度 春期 ITパスポート試験 問93
This question's explanation and your answers so far.
解説
問 93
Incorrectア
Preventing login with the same user ID from another PC while logged in from one PC is an exclusive-control mechanism aimed at preventing simultaneous (concurrent) login; it differs from SSO, which lets you use multiple services with a single authentication, in both purpose and behavior.
- イ
正解 Single sign-on (SSO) is a mechanism whereby, if a user succeeds in authentication just once at the start, they can thereafter use multiple authorized services and systems without going through the authentication procedure again each time. Choice イ describes exactly this behavior, and its point that a single authentication enables access to multiple services matches the essence of SSO, so it is correct. Its main aims are to improve user convenience and, by consolidating where authentication information (ID and password) is managed, to improve operability.
Incorrectウ
Registering on the PC a digital certificate issued by a certificate authority (CA) and using it to verify the user's identity is a description of client-certificate authentication (an authentication method that uses PKI), which is merely one kind of authentication means. It is a different thing from the SSO concept of carrying authentication over to multiple services.
Incorrectエ
Using a disposable password that can be used only once to prevent unauthorized access is a description of a one-time password (OTP). This is a method for strengthening authentication and is unrelated to SSO, which lets you use multiple services with a single authentication.
ここがポイント
- Single sign-on (SSO) = a mechanism that lets you access multiple authorized services and systems with a single authentication and no re-authentication. Its aims are improved convenience and centralized management of authentication information.
- SSO is the concept of carrying authentication over to multiple services; remember it as distinct from specific authentication methods or controls such as exclusive login control, client-certificate authentication, and one-time passwords.
用語