A method of authenticating a user by an authentication server in a networked computer system comprising one or more application server(s) (32, 36), the method comprising: presenting user credentials by a user to a gatekeeper server; providing presented user credentials by the gatekeeper server to an authentication server; authenticating the user by the authentication server; creating an authentication token by the authentication server upon authentication of the user to uniquely identify the user, the authentication token being independent of the user credentials presented by the user and utilized by the application server(s) (32, 36) to verify that the user has been authenticated by the authentication server; encrypting the authentication token by the authentication server using a key not shared with the gatekeeper server; transmitting the authentication token by the authentication server to the application server(s) (32, 26), wherein transmitting the authentication token to the application server(s) (32, 26) comprises transmitting the authentication token by the authentication server to the gatekeeper server and then transmitting the authentication token by the gatekeeper server to the application server(s) (32, 36); creating an outer token by the gatekeeper server; wrapping the outer token around the authentication token to form a combined token; encrypting the combined token by the gatekeeper server using a key not shared with the authentication server; and sending the encrypted combined token to the authenticated user; wherein within one login-session the authenticated user is allowed to subsequently access the application server(s) (32, 36) by presenting the combined token to the gatekeeper server without having to be re-authenticated. presenting user credentials by a user to a gatekeeper server; providing presented user credentials by the gatekeeper server to an authentication server; authenticating the user by the authentication server; creating an authentication token by the authentication server upon authentication of the user to uniquely identify the user, the authentication token being independent of the user credentials presented by the user and utilized by the application server(s) (32, 36) to verify that the user has been authenticated by the authentication server; encrypting the authentication token by the authentication server using a key not shared with the gatekeeper server; transmitting the authentication token by the authentication server to the application server(s) (32, 26), wherein transmitting the authentication token to the application server(s) (32, 26) comprises transmitting the authentication token by the authentication server to the gatekeeper server and then transmitting the authentication token by the gatekeeper server to the application server(s) (32, 36); creating an outer token by the gatekeeper server; wrapping the outer token around the authentication token to form a combined token; encrypting the combined token by the gatekeeper server using a key not shared with the authentication server; and sending the encrypted combined token to the authenticated user; wherein within one login-session the authenticated user is allowed to subsequently access the application server(s) (32, 36) by presenting the combined token to the gatekeeper server without having to be re-authenticated.