METHOD AND DEVICE FOR DETECTING AN ATTEMPT TO SUBSTITUTE AN ORIGINAL CASING PORTION OF AN ELECTRONIC SYSTEM WITH A REPLACEMENT CASING PORTION

摘要

The invention relates to an electronic system comprising a casing consisting of at least first and second casing portions and containing a device for detecting the substitution of the first casing portion. The device comprises a first integrated circuit intended to be fixed to the first casing portion and a second integrated circuit intended to be fixed to the second casing portion. The second circuit is adapted to transmit to the first integrated circuit successive random or pseudo-random digital signals (R). The first integrated circuit is adapted to return to the second integrated circuit, for each digital signal, a first encrypted signature (S) from said digital signal. The second integrated circuit is adapted to determine a second encrypted signature (S') from said digital signal and to detect a substitution of the first casing portion if the first and second encrypted signatures are different.