Improved tamper detection circuit based on linear-feedback shift register

The paper presents an improved method to detect tamper intrusions based on an active circuit. It is composed of a logical part, a microcontroller, capable of generating pulses that follow the rule of a linear-feedback shift register (LFSR), and an analogical part made of a mesh network, used to cover secure modules, and a pulse forming circuit. Pulses resulted from this forming circuit are analyzed by the microcontroller to determine the durations between pulses and the durations of pulses. The novelty of this method is that the pulses are generated synchronously at both ends of the mesh network in order to prevent any attempts of an attacker to break the wire of the mesh network and to simulate the generation of pulses.