Design and implementation of a new blockchain algorithm to increase reliability, security and integrity

The utilization of blockchain is increasing day by day because of its extra ordinary features including distributed and decentralized storage services. Blockchain can provide flexibility, tamper resistance, immutability, fairness, transparency, and robustness. Moreover, the addition of smart contract provides increases the programmability and management facilities. Although blockchain was first introduced to support cryptocurrency, special facilities make it popular for different fields like e-commerce, global payments, P2P landing, remittance, healthcare, record keeping, voting, logistics, etc. Smart devices including internet of things (IoT), internet of vehicles (IoV), internet of healthcare (IoH), etc. also start utilizing blockchain for different purposes. However, too much flow of data and duplication increase the scalability problem and there is no efficient solution available to minimize this problem. Thus, in this thesis, we proposed a novel multi-level blockchain structure to minimize the scalability problem. The system is divided into two parts which are global and local blockchain. Local nodes are the member of a local blockchain where all the local service center is a member of the global blockchain. Global blockchain stores information of all the local blockchains'members. Local service centers will provide their support to only the local members and global blockchain will be used to handle the migration process. Because of the proposed structure, local blockchains will not be overloaded and thus able to perform more efficiently and quickly. To implement the proposed structure, we used Vehicular ad hoc networks (VANET). Smart vehicles while moving around can form a temporary communication with the nearby vehicles to form a VANET to create social networking between them. Blockchain is used by researchers to ensure the security and authenticity of the vehicles, store and analyze traffic events, and also manage and distribute the transmitted messages. However, almost all of them suffered from scalability problem. To minimize this problem, in this thesis, we use blockchain to manage the authenticity and message transmission of both cluster-based and co-operative VANET. Four different systems have proposed in this thesis and implemented in the ethereum blockchain platform and programmed by using smart contracts. Simulation results and performance analysis shows that the proposed methods provide security, integrity, authenticity, tamper free, robustness as well as outperforms previously available systems.