Apparatus for validating the presence of an authorized accessory

摘要

An apparatus for validating the presence of an authorized accessory of the apparatus includes an integrated circuit which stores a secret key K, is configured to define a random number generator which returns R and is configured to apply a function F[R] to return FK[R], based on the secret key K. The apparatus includes a control system which is configured to request FK[R] from the integrated circuit and from a further integrated circuit positioned on the accessory and to compare FK[R] from both the integrated circuits.