Yksittäiskirjautuminen

Yksittäiskirjautuminen, commonly known by its English abbreviation SSO (Single Sign-On), is an authentication scheme that allows a user to log in with a single set of credentials to gain access to multiple independent software systems. Instead of requiring separate usernames and passwords for each application, SSO centralizes the authentication process. When a user successfully authenticates with an SSO system, they are granted access to all connected applications without needing to re-enter their credentials for each one.

The primary benefit of SSO is enhanced user experience. It reduces the number of passwords users need to remember, which in turn decreases password-related support requests and the likelihood of users resorting to weak or reused passwords. For organizations, SSO can improve security by allowing for more robust authentication methods to be implemented at a central point. It also simplifies user management, as administrators can provision or deprovision access to multiple applications simultaneously through the SSO system.

SSO solutions typically rely on protocols like SAML (Security Assertion Markup Language), OAuth, or OpenID Connect. These protocols enable the secure exchange of authentication and authorization data between an identity provider (the SSO system) and service providers (the applications). When a user attempts to access a service provider, they are redirected to the identity provider for authentication. Upon successful login, the identity provider issues a security token that the service provider trusts, granting the user access.