The invention relates to a server system for providing at least one service. The system having an interface for connecting a server to a user's computer, an authentication device that is designed and provided for request personal identification data of a user who logs onto the server via the user computer and to permit the user computer access if authentication is successful, and a server protection system. The server protection system is designed and provides to compare additional user's computer specific identification data with identification data stored in advance on the server, after successful authentication by the authentication device, and to grant authorization to the user's computer to access the service or services depending on the comparison of the user's computer specific identification data. The invention also relates to a method for providing at least one service and the method for executing an application program.