The Trustworthy Autonomic Interface Guardian Architecture for Cyber-Physical Systems

The growing connectivity of cyber-physical systems (CPSes) has led to an increased concern over the ability of cyber-attacks to inflict physical damage. Current cyber-security measures focus on preventing attacks from penetrating control supervisory networks. These reactive techniques, however, are often plagued with vulnerabilities and zero-day exploits. Embedded processors in CPS field devices often possess little security of their own, and are easily exploited once the network is penetrated. We identify four possible outcomes of a cyber-attack on a CPS embedded processor. We then discuss five trust requirements that a device must satisfy to guarantee correct behavior through the device's lifecycle. Next, we examine the Trustworthy Autonomic Interface Guardian Architecture (TAIGA) which monitors communication between the embedded controller and physical process. This autonomic architecture provides the physical process with a last line of defense against cyber-attacks. TAIGA switches process control to a trusted backup controller if an attack causes a system specification violation. We conclude with experimental results of an implementation of TAIGA on a hazardous cargo-carrying robot.