Sentry-NoC: a statically-scheduled NoC for secure SoCs

Abstract

SoC security has become essential with devices now pervasive in critical infrastructure in homes and businesses. Today's embedded SoCs are becoming increasingly high-performance and complex, comprising multiple cores, accelerators, and IP blocks interconnected with a Network-on-Chip (NoC). As these IPs can originate from diverse sources, they cannot be trusted to form the root of trust in SoCs. However, the NoC itself, being the communication backbone linking all IPs, is naturally positioned to be the basis for a secure SoC. Therefore, there is a need for an efficient solution that both meets the stringent requirements of modern embedded SoC designs, while maintaining a high level of security. In this paper, we demonstrate how statically-scheduled NoCs inherently enforce traffic isolation and non-interference of communication. The time-division multiplexing (TDM) of NoC links across applications provably ensures that security properties are fulfilled. However, conventional TDM NoCs are still vulnerable to side-channel attacks. We thus propose temporal and data obfuscation schemes that can be embedded within static TDM NoCs, randomizing source-destination communication patterns and switching activity over the links. Our proposed statically-scheduled Sentry-NoC links up untrusted IP blocks to form a secure SoC. Sentry-NoC targets key security properties to effectively mitigate side-channel attacks with an extremely low overhead, reducing average temporal correlation by 81% and average data correlation by 91%.