The authentication level is set separately for each method of authentication. The value indicates how much to trust an authentication mechanism. Once a user has authenticated, this value is stored in the SSO token for the session. When the SSO token is presented to an application the user wants to access, the application uses the stored value to determine whether the level is sufficient to grant the user access. If the authentication level stored in an SSO token does not meet the minimum value required, the application can prompt the user to authenticate again through a service with a higher authentication level. The default value is 0.
If no authentication level is specified, the SSO token stores the value specified in the Core Authentication attribute Default Authentication Level.