Trust-Based Secure Task Offloading in Digital Twin Empowered Vehicular Edge Computing

Task offloading in Vehicle Edge Computing (VEC) refers to the process whereby computational tasks generated by a vehicle are transferred to and executed by edge servers. This process aims to optimize performance and reduce the vehicle’s computational load by exploiting edge servers’ computational capabilities. However, the lack of trust between participating entities and the unreliability of communication channels cause various threats on communication and data exchange. Motivated by this discussion, in this paper, we present a framework integrating blockchain and digital twin (DT) to secure task offloading operations from mobile vehicles to edge servers. The framework first presents a novel DT-enabled computation offloading model that facilitates and minimizes the cost of communication between physical entities. Secondly, we propose a trust evaluation system based on subjective logic that considers temporal correlation and focuses on current behavior for the calculation of entity reputation. To ensure reliable management of reputation score values, we have used blockchain to store these scores in a distributed and immutable manner. Intensive experimentation has demonstrated the good performance of the proposed framework in terms of early detection of malicious nodes, reliable offloading communications, and high data confidentiality thanks to DT and blockchain.