Enhancing the efficiency and scalability of blockchain through probabilistic verification and clustering

Abstract Blockchain is a disruptive technique that finds many applications in FinTech, IoT, and token economy. Because of the asynchrony, the competitive mining, and the indeterministic block propagation delay in networks, forks in the blockchain occur frequently, which not only waste a lot of computing resources but also result in potential security issues. This issue will greatly affect the efficiency of blockchain networks. In the meantime, when blockchain networks expand, the storage data for each node will be increasing dramatically. Participates are about to face the problem of storage limitation. Blockchain is hard to scale. This paper introduced PvScheme, a probabilistic verification scheme that could effectively reduce the block propagation delay and reduce the occurrence of blockchain forks. We further enhanced the security of PvScheme to provide reliable block delivery. We also analysed the resistance of PvScheme to fake blocks and double spending attacks. Furthermore, we proposed ICIStrategy, a multi-node collaborative storage strategy based on intra-cluster integrity. In ICIStrategy, we divided all participates into several clusters. Each cluster requires holding all data of the network, whereas a node within the cluster does not need to maintain data integrity. It aims to solve the storage pressure by reducing the amount data that each participate need to store and reduce communication overhead by collaboratively storing and verifying blocks through in-cluster nodes. We designed the experiments to study the performance of PvScheme and ICIStrategy. The experiment results illustrated that PvScheme could reduce the propagation delay of the standard protocol by 43.1% when the validation degree was 0.5. And we got the best effect when the validation degree is 0.9. It got a relatively lower forks and a relatively higher security at the same time, which achieved a compromise between the efficiency and security in the blockchain. According to the experimental results, ICIStrategy decreased effectively the storage of each node. And the larger the scale of networks, the less the storage of each node.