Study On Consortium Blockchain Security Mechanism And Its Application In Copyright Protection

Consortium blockchain technology is widely used in various data storage businesses because of its characteristics such as data immutability,decentralization.With the development of the consortium blockchain technology,Hyperledger Fabric consortium blockchain,which has the advantages of modularity and high throughput,has become the mainstream choice for decentralized copyright protection organizations.However,Hyperledger Fabric sacrifices certain security in consensus mechanism and architecture in order to meet the demand for high throughput.How to improve the security of the consortium blockchain under the premise of ensuring high throughput is still a problem worthy of research and improvement.In this thesis,we address the problems of the Hyperledger Fabric consortium blockchain’s endorsement mechanism,Raft consensus algorithm and consortium blockchain architecture in terms of copyright protection where nodes are vulnerable to attacks,Byzantine fault tolerance is not supported,and performance bottlenecks caused by concurrent transactions.A Hyperledger Fabric consortium blockchain endorsement mechanism optimization algorithm based on verifiable random functions and an improved Raft consensus algorithm are designed,and a dual-chain architecture copyright protection model based on sidechain verification is proposed.The main work of this thesis is as follows:(1)A verifiable random function based on elliptic curve is designed,by which a random selection algorithm of Hyperledger Fabric consortium blockchain endorsement nodes is implemented.The algorithm can avoid attackers from targeting the backing nodes.Further,the concurrent processing of transactions by backing nodes is achieved by randomly selecting different sets of backing nodes to execute transactions.The given algorithm enhances the security of the backing nodes compared to the original algorithm,reduces the overall waiting time of transactions,and improves the speed of reaching consensus in the system.(2)An improved Raft consensus algorithm is proposed.This consensus algorithm uses a verifiable random function to extract and verify the Leader nodes in the Leader election phase.A Byzantine fault-tolerant response mechanism is also designed for the log replication phase to ensure that tampered log items cannot reach consensus.The improved Raft consensus algorithm increases the Byzantine fault tolerance and improves the throughput of the system when the number of nodes increases.(3)A copyright protection model for dual-chain architecture based on sidechain verification is designed to address the organizational malpractice problem faced in decentralized copyright protection organizations.The model enhances the security and extensibility of the model by limiting the power of different types of nodes through authority control and isolating sensitive data between different organizations from each other.