In the Internet of Vehicles (IoV), vehicles communicate wirelessly with other vehicles, sensors, pedestrians, and roadside units. IoV is aimed at improving road safety, driving comfort, and traffic efficiency. However, IoV is exposed to a range of threats to security and privacy. The presence of dishonest and misbehaving peers in the system is of a major concern, which may put lives in danger. Thus, establishing trust among these probable untrusted vehicles is one of the most significant challenges of such a network. The critical pitfalls of existing and traditional mechanisms are scalability, a single point of failure, maintaining the quality of service, verification, and revocation and dealing with sparsity, consistency, availability, efficiency, robustness, privacy concerns are some of the biggest challenges to be addressed. Blockchain technology, with its great success in applications like cryptocurrencies and smart contracts, is considered as one of the potential candidates to build trust in IoV. In this paper, we propose a blockchain-based decentralized trust management scheme using smart contracts. Specifically, we introduce the concept of blockchain sharding for reducing the load on the main blockchain and increasing the transaction throughput. Our proposal has two key contributions: blockchain to maintain and update reliable and consistent trust values across the network and incentive scheme to encourage peers to perform well. We also conduct extensive experiments, which demonstrate the implementation feasibility of proposed mechanisms in the real world.

Swarm robotics is an emerging robotic domain that aims to accomplish complex tasks with the cooperative effort of a group of simple robots. These robots communicate and share information to coordinate their actions for achieving a common goal. However, existing mechanisms of control and communications are not very secure, efficient, and also rely on centralized controlling authority. It is not flexible, and also has low transparency and tracking capabilities. Blockchain, a decentralized technology based on peer to peer communication along with smart contracts, can be a potential contender for addressing these challenges. However, blockchains are resource‐intensive and not found suitable for resource‐constrained devices. We propose a blockchain‐based framework, which is based on Proof‐of‐Authority (PoA) consensus mechanism to ensure efficiency. We experiment with test‐bed implementation using RaspberryPi. The results obtained demonstrate that the PoA mechanism is not a resource‐hungry one (unlike other state‐of‐the‐art consensus mechanisms). The blockchain with PoA in swarm robotics can provide the necessary security, transparency, decentralization, reliability, autonomy, etc.