Exploiting PUF Unreliability to Secure Wireless Sensing

Wireless sensors attract increased attention from both academia and industry owing to emerging applications such as Internet of Things (IoT), smart homes, e-health, etc. It is widely accepted that security assessment to this super large distributed ubiquitous devices and privacy of collected data are ultimate important, Sensor security that relies on traditional cryptography is vulnerable to various attacks and usually does not lend itself to low-cost and lightweight applications. To overcome it, this paper proposes an alternative secure wireless sensing approach that is suitable for those resource-restricted IoT devices. In particular, we exploit the unreliability of a physical unclonable function (PUF) that is sensitive to ambient environmental variations to guarantee the veracity of the sensed value. In this case, the PUF itself acts as a sensor or is integrated with a sensor, called a PUF sensor. Thus, for a PUF sensor, the processes of cryptography and sensing are inseparable. In our security analyses, it is assumed that i) the PUF sensor is located in a hostile environment, ii) the communication channel is insecure, and iii) no pricey crypto module relying on stored secret keys is involved. Even under such cases, the PUF sensor still provides high level security at lowcost. In addition, the PUF sensor is inherently unclonable. We validate such an alternative wireless sensing approach based on an proof-of-concept experimental implementation of the proposed PUF sensor.