On the use of Forward Body Biasing to decrease the repeatability of laser-induced faults

This paper presents a study on the effect of Forward Body Biasing on the laser fault sensitivity of a CMOS 90nm microcontroller. Tests were performed on a register of this target, under several supply voltage and body bias settings, showing significant laser sensitivity variations. Based on these results, a method which aims at decreasing fault repeatability by using variable supply voltage and body bias settings is proposed. Finally, tests are performed on an implementation of this method on a temporally redundant AES and the results are presented.