Testing Feasibility of Back-Side Laser Fault Injection on a Microcontroller

Laser fault attack platform constitutes a powerful tool for a precise injection of faults into the device, allowing an attacker to carefully adjust timing and position on the chip. On the other hand, the cost of such equipment is high and the profiling time is non-negligible. In this paper, we would like to investigate the practicability of the back-side laser fault injection and to state benefits and drawbacks of this technique. We performed experiments on two methods of fault injections induced by a laser beam -- instruction disturbance experiments and register value changes. The first method, as our experiments show, is easy to perform, precise and repeatable. The second one is harder to perform and we could not achieve repeatability in such experiments.