Prüfung der Berechtigung der Installation einer Softwareversion

摘要

A method of maintaining a version counter indicative of a version of memory content stored in a processing device. The method comprises selectively operating the device in a first or second mode. Access to the first mode is limited to authorised users and controlled separately from access to the second mode. In the first mode at least an initial integrity protection value is generated for cryptographically protecting an initial counter value of said version counter during operation of the processing device in the second mode; wherein the initial counter value is selected from a sequence of counter values, and the initial integrity protection value is stored as a current integrity protection value in a storage medium. In the second mode, a current counter value is incremented to a subsequent counter value; wherein incrementing includes removing the current integrity protection value from said storage medium.