Research On Blockchain Consensus Mechanism For Wireless Distributed System

The wireless distributed system has challenges in terms of scalability,security and privacy protection,and inter-network collaboration.Due to the characteristics of tamper-proof and decentralization,blockchain can reduce the operation and maintenance costs of the wireless distributed system,strengthen the security of user data and privacy,help to trace the source of data in the system,break the shackles of information islands in the wireless distributed system,and promote inter-network collaboration.Consensus mechanism is the key technology of blockchain,which plays an important role in the combination of the wireless distributed system and blockchain.Proof-based consensus mechanisms represented by proof-of-work and voting-based Byzantine consensus represented by practical Byzantine fault tolerance are widely used in wireless distributed systems.However,the application of the blockchain based on these two types of consensus mechanisms in the wireless distributed system has the following problems: first,the nodes of the wireless distribution system have self-interested behavior,which threatens the security of the system consensus;secondly,the limited communication resources of wireless distribution system lead to the reduction of consensus efficiency;finally,the scalability of Byzantine consensus is poor,which cannot meet the requirements of large-scale wireless distribution systems.Therefore,this paper studies and designs a consensus algorithm for wireless distributed systems.The specific research contents and contributions of this dissertation are summarized as follows:1.A dynamic computing power infiltration attack method is proposed for the wireless distributed system based on proof-of-work,which seriously reduces the resource utilization rate of the wireless distribution system consensus.Based on the game theory,the effectiveness of the attack is analyzed,and the optimal attack strategy is given.From the perspective of the system,the impact of the deployment of computing power resources on resisting attacks is analyzed.The results show that reasonable deployment of computing power can effectively avoid the degradation of system performance caused by the self-interested behavior of distributed nodes.2.Aiming at the mobile ad hoc characteristics of the wireless distribution system,a leaderless weakly synchronous Byzantine fault tolerance(LBFT)consensus mechanism is proposed,which includes a weak synchronous reliable broadcast protocol(WRBC)with one-half fault tolerance for reliable broadcasting of information between nodes,a weakly synchronous binary Byzantine consensus protocol(WBA)with one-half fault tolerance for distributed decision-making.We prove the correctness of the LBFT protocol,which includes safety and liveness.Finally,the simulation experiment verifies that the LBFT protocol is superior to the Sync Hot Stuff protocol and the SMR-BFT protocol in the rotating leader mode in terms of throughput and delay.3.For a sharding-based consensus system,a leaderless sharding permissioned blockchain(LSchain)is proposed,which improves scalability while ensuring deterministic security,fairness,and high fault tolerance.In LSchain,a directed acyclic graph-based distributed ledger is designed.And then,a low-communication-complexity improved leaderless cross-shard Byzantine fault tolerance protocol(ILCBFT)is proposed,and the security and liveness of the protocol are proved.Simulation results show that the proposed consensus protocol with low communication complexity has better parallel transaction processing ability and better scalability.4.In the wireless distribution system based on the sharding permissioned blockchain,the system communication and computing resources are limited,and the transaction load among shards is unbalanced,which will threaten system stability and reduce transaction throughput.Therefore,considering unbalanced transaction allocation or even malicious transaction injection attacks,we study how to flexibly allocate resources for each network shard,so as to meet the minimum transaction processing delay requirements of each network shard,and ensure the stability of each network shard queue.First,we use the non-cooperating game to formulate the resource allocation among shards.Then,based on Lyapunov optimization and Lagrangian dual decomposition,we propose a dynamic distributed resource allocation algorithm,and analyze the theoretical boundaries of each network fragmentation target and fragmentation queue length.Finally,the numerical results show that our proposed distributed resource allocation algorithm can achieve a better balance between queue stability and resource consumption than other resource allocation algorithms under the premise of satisfying resource constraints.