Identity data of an operational unit and a verification key of the cryptographic method employed by the service provider are protected with a key of the cryptographic method employed by the manufacturer of the operational unit. The verification key of the cryptographic method employed by the manufacturer of the operational unit is stored in the operational unit of the electronic device. The identity data of the operational unit and the identity data of the service provider are protected with a key of the cryptographic method employed by the service provider. The identity data of the operational unit and the verification key of the service provider are verified with the verification key of the manufacturer of the operational unit. The identity data of the operational unit and the identity data of the service provider are verified with the verified verification key of the service provider. The identity data stored in the user-specific module are compared with the verified identity data. The device starts if the identity data verified by the cryptographic method correspond with the identity data stored in the user-specific module.