問62
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22年度 秋期 ITパスポート試験 問62
This question's explanation and your answers so far.
解説
問 62
Incorrectア
Receiving authentication separately for each system is the conventional way of working before single sign-on is introduced. SSO is introduced precisely to remove the effort of the user entering an ID and password over and over, and the reuse and cumbersome management of passwords, so ア describes a state that is rather the opposite of SSO.
- イ
正解 Single sign-on (SSO) means that once the user is authenticated (logs in) just one time at the start, that authentication result is also treated as valid by the linked systems, so the user can go on using the multiple systems they have been authorized to use without re-entering an ID and password for each system. Choice イ, “the user can use multiple authorized systems after receiving authentication only once”, states exactly this definition. It is accurate in covering the two key points, a single authentication and multiple systems within the permitted (that is, authorized) scope, and so it is the correct answer.
Incorrectウ
Accessing a service on the network and completing the membership registration procedure is a description of user registration (creating an account). Membership registration is the task of newly registering a user, while authentication is the task of confirming that an already registered user is really that person; they are different stages. SSO is a technology that reduces the number of authentications, not the registration procedure itself.
Incorrectエ
Changing the password when accessing with the distributed initial password is a description of a basic rule of password operation management (the forced change of an initial password). It is an operational measure for keeping passwords safe, and has nothing to do with a mechanism that makes multiple systems usable with a single authentication.
ここがポイント
- Single sign-on (SSO) = a mechanism that lets a user use multiple authorized systems and services after being authenticated only once. Its advantages are that it reduces the user's input effort and allows IDs to be managed centrally; at the same time, remember its weakness, that if this one set of credentials leaks, the impact reaches multiple systems all at once.
- Authentication (confirming that the person is who they claim to be), authorization (granting how far they may use something), and user registration (membership registration) are different concepts. SSO is a technology that consolidates authentication into a single time, and as the wording “authorized” indicates, which systems can be used is determined by the scope of authorization.
用語