The Impact of Pulsed Electromagnetic Fault Injection on True Random Number Generators

Random number generation is a key function of today's secure devices. Commonly used for key generation, random number streams are more and more frequently used as the anchor of trust of several countermeasures such as masking. True Random Number Generators (TRNGs) thus become a relevant entry point for attacks that aim at lowering the security of integrated systems. Within this context, this paper investigates the robustness of TRNGs based on Ring Oscillators (focusing on the delay chain TRNG) against pulsed electromagnetic fault injection. Indeed, weaknesses in generating random bits for masking scheme degenerate the Side Channel resistance. Finally by exploiting fault results on delay chain TRNG some general guidelines to harden them are derived.