Sensory channel threats to Cyber Physical Systems: A wake-up call

Cyber-Physical Systems (CPS) is a relatively novel computing paradigm where there is a tight integration of communications, computation, and the physical environment. An important component of the CPS devices is the sensors they use to interact with each other and the physical world around them. With CPS applications, engineers monitor the structural health of highways and bridges, farmers check the health of their crops, and ecologists observe wildlife in their natural habitat. Nonetheless, current security models consider protecting only networking components of the CPS devices utilizing traditional security mechanisms (e.g., an intrusion detection system for the data that traverse the network protocol stacks). The protection mechanisms are not sufficient to protect CPS devices from threats emanating from sensory channels. Using sensory channels (e.g., light, temperature, infrared), an adversary can successfully attack systems. Specifically, the adversary can (1) trigger existing malware, (2) transfer malware, or (3) combine malicious use of different sensory channels to increase the impact of the attack on CPS devices. In this work, we focus on these novel sensory channel threats to CPS devices and applications. We first note how sensory channel threats are an emerging area for the CPS world. Then, we analyze the performance various sensory channel threats. Moreover, using an iRobot Create as our CPS platform, we exploit simple vulnerable programs on iRobot through its infrared channel. Finally, we introduce the design of a novel sensory channel aware intrusion detection system as a protection mechanism against the sensory channel threats for CPS devices.