Abstract: A method for producing a control device includes the following steps: generating, by the control device, a first asymmetric cryptographic key pair with a first private key and a first public key; transmitting the first public key to an external entity; generating, by the external entity, a second asymmetric cryptographic key pair with a second private key and a second public key; encrypting, by the external entity, the second private key using the first public key; transmitting the encrypted second private key from the external entity to the control device; and decrypting, by the control device, the encrypted second private key using the first private key.

Abstract: A method for the authentication on a device includes a step of providing a certificate, the certificate enabling a limited number N of authentication processes. The method further includes a step of carrying out an authentication process on the device, and a step of reducing the number N of authentication processes that are still possible for the certificate.

Abstract: The invention relates to a freely activatable hydraulic valve control device for a stroke valve, which valve control device is arranged particularly in an internal-combustion engine. The stroke valve includes a valve stem and a first spring acting on the valve stem in the valve-closing direction as well as a second spring acting at least periodically on the valve stem in the valve-opening direction. The valve stem is connected at least to a control piston arranged in a working space and capable of being loaded on two sides with a working fluid. The pressure of the working fluid in the working space can be regulated via a pressure source together with a switching valve and a supply conduit.