Cyber-Physical Systems Attestation

Abstract

Cyber-Physical Systems (CPS) are monitored and controlled by a wide variety of sensors and controllers. However, it has been repeatedly demonstrated that most of the devices interacting with the physical world (sensors and controllers) are extremely fragile to security incidents. One particular technology that can help us improve the trustworthiness of these devices is software attestation. While software attestation can help a verifier check the integrity of devices, it still has several drawbacks that have limited their application in the field, like establishing an authenticated channel, the inability to provide continuous attestation, and the need to modify devices to implement the attestation procedure. To overcome these limitations, we propose CPS-attestation as an attestation technique for control systems to attest their state to an external verifier. CPS-attestation enables a verifier to continuously monitor the dynamics of the control system over time and detect whether a component is not behaving as expected or if it is driving the system to an unsafe state. Our goal in this position paper is to initiate the discussion on the suitability of applying attestation techniques to control systems and the associated research challenges.