A method includes a step of generating, using a control device, a private key and a public key, a step of acquiring, using the control device; encrypted data obtained by encrypting the data using the public key; a step of decrypting, using the control device, the private key for the encrypted data when the control device performs a process; a step of storing, using the control device, the data obtained by decrypting the encrypted data using the private key in a volatile storage area that is not accessible from the outside; and a step of executing, using the control device, a process with reference to the data stored in the storage area.

According to an aspect of the invention a configuration method for configuring a host device in a control system is conceived, in particular a building control system, wherein an authorized configuration device exchanges confidential configuration data with a radio frequency identification tag coupled to the host device, wherein, after the confidential configuration data have been exchanged and a corresponding configuration operation has been performed, access to the confidential configuration data by an unauthorized configuration device is precluded. According to further aspects of the invention a corresponding configuration device, a corresponding computer program product and a corresponding control system are conceived.