Programmable RO (PRO): A Multipurpose Countermeasure Against Side-Channel and Fault Injection Attack

This chapter introduces a novel approach to address side-channel and fault injection attacks on FPGAs that exploit physical effects in computations involving secret variables. Instead of using separate countermeasures for each attack vector, this chapter proposes a versatile solution called the Programmable Ring Oscillator (PRO). PRO is an integrated primitive that can offer on-chip side-channel resistance, power monitoring, and fault detection capabilities in a generic and application-independent manner. The PRO is deployed in a grid across the on-chip power network to detect anomalies caused by external factors such as electromagnetic fault injection, power glitches, or internal factors such as hardware Trojans. By monitoring the frequency of ring oscillators, power anomalies can be timely identified and localized. Additionally, PROs are capable of injecting a random noise pattern into a design’s power consumption. By switching the frequency of a ring oscillator randomly, the resulting power-noise pattern significantly reduces power-based side-channel leakage of a cipher. Measurement results on a Xilinx Spartan-6 FPGA prototype demonstrate that the PRO approach effectively addresses side-channel and fault vulnerabilities at a low cost. This multipurpose countermeasure offers a practical and efficient solution to enhance the security of various designs, making it a promising advancement in hardware security against diverse attack vectors.