Thermo-Attack Resiliency: Addressing a New Vulnerability in Opto-Electrical Network-on-Chips

Optical Network-on-Chip (ONoC) has recently emerged as a power- and latency-efficient solution to improve the performance of Multi-Processor System-on-Chips (MPSoCs). ONoCs utilize optical communications to transfer a bulk of data with significantly reduced energy consumption compared to their electrical counterparts. However, the temperature sensitivity of optical routers might be exploited by adversaries to conduct thermal attacks on the optical components of such MPSoCs. In this paper, for the first time, we exploit this vulnerability and define three variations of a thermal attack on optical and electrooptical MPSoCs. The proposed attack alters the functionality of an MPSoC by inducing a range of malicious activities, including 1) Packet misdelivery, drops, and losses; 2) Data errors in normal and secure packets; and 3) Putting the network in a deadlock situation. In addition to defining the thermal attack, the paper proposes the application of stochastic source routing to protect MPSoCs against thermal attacks. This approach enhances the security of MPSoCs by making it challenging for the adversary to identify and track packets. Our evaluations validate the effectiveness of the proposed countermeasure.