BlockchainBased Lightweight Trust Management in Mobile AdHoc Networks As a trending and interesting research topic, in recent years, researchers have been adopting the blockchain in the wireless adhoc 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 an adhoc network is which kind of nodes should be involved in the validation process and how to adopt the heavy computational complexity of block validation appropriately while maintaining the genuine characteristics of a blockchain. In this paper, we propose the blockchainbased trust management system with a lightweight consensus algorithm in a mobile adhoc network (MANET). The proposed scheme provides the distributed trust framework for routing nodes in MANETs that is tamperproof 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, blockchain solves 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 experimental results show that the proposed consensus algorithm is suitable to be used in the resourcehungry MANET with reduced validation time and less overhead. Meanwhile, the attack detection overhead and time also decrease because the repetitivity of the process is reduced while providing a scalable and distributed trust among the routing nodes.

Hash Access: Trustworthy GrantFree IoT Access Enabled by Blockchain Radio Access Networks The explosion of Internet of Things (IoT) applications makes the existing network structure insufficient because it is split by multiple noncooperative operators, does not scale with the future development of IoT, and calls for novel networking concepts and protocols. The need for multioperator IoT paradigms poses some unprecedented challenges, including trust considerations. To enable a multioperator network without shared authentication, we propose a trustworthy grantfree IoT access protocol named Hash Access by leveraging a blockchain radio access network (BRAN) architecture. BRAN reorganizes multiple individual radio access networks into a joint multioperator network based on a blockchain. BRAN can establish trust among initially trustless operators and efficiently utilize resources across networks, matching and creating values for multiple participants. Furthermore, to mitigate the loss of network efficiency caused by selfish behavior among untrustworthy IoT devices, the proposed protocol can induce IoT devices to follow an access rule and control their data traffic. The proposed framework unifies the IoT access and the underlying BRAN to reduce confirmation delays in traditional blockchains significantly. Numerical experiments illustrate the performance edge for the BRANenabled Hash Access.