A Two-level Integrated Approach for Assigning Trust Metrics to Internet of Things Devices

The Internet of Things (IoT) is the next step of the Internet evolution and it is paving the way for the development of Cyber-Physical Systems (CPS). It will enable the development of a plethora of new systems and applications. The massive, ubiquitous spread of interconnected IoT devices has increasingly exposed the vulnerability of data and related applications in an unprecedented way. If the security of any component in such systems gets compromised, an associated data leak may cause serious threats to privacy, material losses, and even put people's lives at risk. Therefore, studies on IoT security aspects have become increasingly important. This paper presents a proposal to deal with the still open issue related to trust aspects of IoT systems. The key idea consists of a two-level approach to simultaneously consider application and network characteristics, in which trust is modeled by combining a relative entropy measure of device's data rate (at the low level), and a reputation of a device provided by distributed-ledger (at the high level). Numerical results show the effectiveness of the proposed approach in isolating anomalous/untrusted devices based on their acquired reputation and on the respective changes in data rate behavior.