Mobile devices are in roles where the integrity and confidentiality of their apps and data are of paramount importance. They usually contain a System-on-Chip (SoC), which integrates microprocessors and peripheral Intellectual Property (IP) connected by a Network-on-Chip (NoC). Malicious IP or software could compromise critical data. Some types of attacks can be blocked by controlling data transfers on the NoC using Memory Management Units (MMUs) and other access control mechanisms. However, commodity processors do not provide strong assurances regarding the correctness of such mechanisms, and it is challenging to verify that all access control mechanisms in the system are correctly configured. We propose a NoC Firewall (NoCF) that provides a single locus of control and is amenable to formal analysis. We demonstrate an initial analysis of its ability to resist malformed NoC commands, which we believe is the first effort to detect vulnerabilities that arise from NoC protocol violations perpetrated by erroneous or malicious IP.
The need for security in embedded systems has strongly increased since several years. Nowadays, it is possible to integrate several processors in a single chip. The design of such multiprocessor systems-on-chip (MPSoC) must be done with a lot of care as the execution of applications may lead to potential vulnerabilities such as revelation of critical data and private information. Thus it becomes mandatory to deal with security issues all along the design cycle of the MPSoC in order to guarantee a global protection. Among the critical points, the protection of the communications is very sensible as most of the data are exchanged through the communication architecture of the system. This paper targets this point and proposes a solution with distributed enhancements to secure data exchanges and to monitor communications within a MPSoC. In order to validate our contribution, a case study based on a generic multiprocessor architecture is considered. Security in MPSoC is gaining an increasing attention since several years. Digital convergence is one of the numerous reasons explaining such a focus on embedded systems as much sensitive and secret data are now stored, manipulated and exchanged in these systems. Most solutions are currently built at the software level, we believe hardware enhancements also play a major role in system protection. One strategic point is the communication layer as all data goes through it. Monitoring and controlling communications enable to fend off attacks before system corruption. In this work, we propose an efficient solution with several hardware enhancements to secure data exchanges in a bus-based MPSoC. Our approach relies on low complexity distributed firewalls connected to all critical IPs of the system. Designers can deploy different security policies (access right, data format, authentication, confidentiality) in order to protect the system in a flexible way. To illustrate the benefit of such a solution, implementations are discussed for different MPSoCs implemented on Xilinx Virtex-6 FPGAs. Results demonstrate a reduction up to 33 in terms of latency overhead compared to existing efforts.