A token is a digital object used to authenticate a user's identity in Single Sign-On (SSO) systems.
Description
In the context of Single Sign-On (SSO) protocols, a token is a piece of data that represents a user's identity and permissions after they have successfully logged into a system. When a user authenticates using their credentials, the SSO service generates a token, which is then passed to other applications or services that the user wants to access. This token serves as proof that the user has been authenticated and is authorized to access the requested resources without needing to log in again. Tokens typically include information such as user identity, expiration time, and the scope of access. Common token formats include JSON Web Tokens (JWT) and Security Assertion Markup Language (SAML) tokens. The use of tokens enhances security by reducing the number of times a user must enter their credentials and minimizes the risk of password theft since credentials are only transmitted once during the initial login.
Examples
- Google's OAuth 2.0 uses access tokens to grant users access to third-party applications without sharing their passwords.
- Microsoft Azure Active Directory issues tokens to authenticate users across various Microsoft services like Office 365.
Additional Information
- Tokens can have different expiration times, enhancing security by limiting the duration of access.
- Using tokens reduces the risk of session hijacking as they are not tied to the user's session directly.