UASTrustChain: A Decentralized Blockchain- Based Trust Monitoring Framework for Autonomous Unmanned Aerial Systems

Unmanned aerial systems (UASs) are prone to several cyber-physical attacks, which decrease the performance of the network and may cause damage to the unmanned aerial vehicles (UAVs) or their surrounding environment. In this article, we propose UASTrustChain, a trust management framework based on Blockchain time-stamped series. We consider a system of models, consists of a number of autonomous UAVs, whose behaviors are regularly monitored by a set of distributed observers (DOs). Since most cyber attacks cause interruption in the operations of UAVs or deviation from their original path, the DOs keep track of the UAVs' behavior in terms of their trajectory, as well as the number of their successful tasks. The DOs calculate a relative trust score for each UAV and keep these scores in a transparent, reliable, secure and open ledger. This framework can detect UAVs' abnormal behavior in a real-time manner further to detect the compromised distributed observers, if any. The proposed framework could also distinguish abnormal activities due to real attacks from those caused by harsh environmental conditions. We evaluate the proposed framework for its functionality and accuracy by performing extensive simulation experiments. Our simulation results show that the proposed trust model can detect compromised distributed observers and fades their effect on the UAVs trust scores. Results further show the ability of the system in detecting malicious UAVs, which can be under various cyber-physical attacks.