Language semantics to support secure computation and communication in embedded systems via hardware monitors

Abstract

As embedded systems with manycores and Network-on-Chips (NoCs) become ubiquitous, emerging hardware and software vulnerabilities have made it challenging to ensure system integrity especially when third-party intellectual property (IP) is used for rapid prototyping. Prior works have evaluated hardware monitors for ensuring correctness of the system by threat assessment and effective mitigation. However, none have evaluated models that combine both computation (processor pipeline) and communication (NoC) vulnerabilities simultaneously. In this paper, we propose a high-level policy language called d-GUARD that is used to define runtime security policies that can be compiled into hardware monitors. The advantage of this new language is the ability to dynamically change policies based on program’s runtime behavior. To translate high-level policies into low-level hardware monitors, we describe a compiler for d-GUARD that synthesizes policies into Verilog modules. Instead of simply evaluating the design of secure policies for processor pipelines, we extend to secure NoC microarchitectures, including policies for links and routers, as well as policies to prevent Denial-of-Service (DoS) attacks. To mitigate attacks against secure microarchitectures, we also propose fault-tolerant routing approaches to avoid rogue routers when the number of policy violations exceeds a certain threshold. Our secure policies for processor pipelines and NoC microarchitectures consume marginal area and power overhead when compared to baseline making it well suited for low-cost embedded systems.