Single Sign-On

Single Sign-On (SSO) is an authentication process that allows a user to access multiple applications or services with a single set of login credentials (such as username and password). The primary goal of SSO is to simplify the user experience by eliminating the need for users to remember and manage multiple sets of credentials for different applications or websites.

Key features and concepts of Single Sign-On include:

1. Authentication:
   • SSO involves a centralized authentication system where users authenticate once and obtain credentials (e.g., tokens or tickets) that grant them access to multiple applications or services without the need to reauthenticate for each one.
2. Identity Provider (IdP):
   • The Identity Provider is a centralized service responsible for authenticating users and issuing authentication tokens. It serves as the authoritative source for user identity information. Popular identity providers include Okta, Microsoft Azure Active Directory, and Google Identity Platform.
3. Service Provider (SP):
   • A Service Provider is an application or service that relies on the Identity Provider for authentication. The Service Provider trusts the authentication tokens issued by the Identity Provider to grant access to authenticated users.
4. User Authentication Flow:
   • When a user attempts to access a Service Provider, the Service Provider redirects the user to the Identity Provider for authentication. After successful authentication, the Identity Provider issues a token to the user, who is then redirected back to the Service Provider with the token.
5. Single Sign-On Protocols:
   • Several protocols are used to implement SSO, including:
     • SAML (Security Assertion Markup Language): A standard for exchanging authentication and authorization data between parties, particularly between an Identity Provider and a Service Provider.
     • OAuth (Open Authorization): A framework for granting limited access to resources without sharing credentials, often used for delegated access.
     • OpenID Connect: An authentication layer built on top of OAuth 2.0, providing identity services and additional features for user authentication.
6. Session Management:
   • SSO systems typically manage user sessions and ensure that users remain authenticated across multiple applications during a specified period. This is done through the use of tokens that represent the user’s identity and session state.
7. User Provisioning and De-Provisioning:
   • SSO systems often include user provisioning and de-provisioning capabilities. When a new user is added or removed from the organization, the changes are reflected across all connected applications.
8. Security and Federated Identity:
   • SSO enhances security by reducing the need for users to manage multiple passwords, which can lead to better password hygiene. Additionally, it allows organizations to implement federated identity, where trust relationships are established between the Identity Provider and various Service Providers.
9. Cross-Domain SSO:
   • SSO can be implemented across different domains or organizations, enabling users to access resources seamlessly across multiple entities without needing separate credentials for each.
10. Single Log-Out:
    • SSO systems often support Single Log-Out, allowing users to log out from all connected applications simultaneously with a single action.

SSO is widely used in various industries and is a common feature in enterprise environments, web applications, and cloud-based services. It simplifies user authentication and access management while improving overall security and user experience.