As a trending and interesting research topic, in recent years, researchers have been adopting the blockchain in the wireless ad-hoc environment. Owing to its strong characteristics, such as consensus, immutability, finality, and provenance, the blockchain is utilized not only as a secure data storage for critical data but also as a platform that facilitates the trustless exchange of data between independent parties. However, the main challenge of blockchain application in ad-hoc network is which kind of nodes should involve in the validation process and how to adopt the heavy computational complexity of block validation appropriately while maintaining the genuine characteristics of blockchain. In this paper, we propose the blockchain-based trust management system with lightweight consensus algorithm in mobile ad-hoc network (MANET). The proposed scheme provides the distributed trust framework for routing nodes in MANETs that is tamper-proof via blockchain. The optimized link state routing protocol (OLSR) is exploited as a representative protocol to embed the blockchain concept in MANETs. As a securely distributed and trusted platform, the blockchain solves the problem of most of the security issues in the OLSR, in which every node is performing the security operation individually and in a repetitive manner. Additionally, using predefined principles, the routing nodes in the proposed scheme can collaborate to defend themselves from the attackers in the network. The experiment results show that the proposed consensus algorithm is suitable to be used in the resource-hungry MANET with the short validation time and less overhead. Meanwhile, the attack detection overhead and time also decrease since the repetitivity of the process is reduced while providing a scalable and distributed trust among the routing nodes.
