Effective Byzantine Fault Tolerance Algorithm Based On Structured Network And Trusted Execution Environment

As the underlying technology of Bitcoin,the blockchain fundamentally establishes a mechanism of trust and value transfer,which promotes the transformation of the information Internet to the value Internet.Although the blockchain originated from Bitcoin,in the course of ten years of development,the blockchain has surpassed the application in the financial field and gradually entered various social fields to provide more complex logic processing capabilities.The bottleneck of blockchain is mainly concentrated on its performance problems of low throughput and high latency,which is actually the result of the trade-off between decentralization and efficiency.Classic distributed consensus algorithms such as Paxos and Raft cannot solve the Byzantine fault tolerance problem,however,the consensus algorithms of public chain systems such as Po W and Po S cannot meet the performance requirements in specific scenarios due to their huge energy costs or design defects of the protocol itself.In contrast,the BFT(Byzantine Fault Tolerant)consensus algorithm can tolerate a certain number of nodes to deviate from the protocol in any way.Byzantine error is the worst-case error in distributed systems.The BFT consensus algorithm provides 100% security rather than probability,but it has not been widely used due to its high resource consumption and low consensus efficiency.In this paper,we propose Loop-Grouping Tree and TEE BFT(Lg TTBFT),a simple and efficient Byzantine fault tolerant consensus strategy.At the heart of Lg TTBFT is a new tree topology(Lg Tree)and Trusted Execution Environment(TEE).The use of TEE has greatly improved system efficiency from both the number of replicas and the communication process: Reduced the minimum number of replicas from 3f +1 to 2f +1;The communication phase of the consensus process is reduced from three phases of PBFT to two phases,and the communication complexity of the PREPARE phase is reduced from O(n2)to O(n).The Algorithm constructed a structured network and multi-reconstructed multi-way tree structure Lg Tree as the node organization structure of the network layer of the blockchain system.Compared with Min BFT and Ethereum,it has the following advantages:1)It provides a simpler network structure and more efficient routing efficiency2)The special tree structure also performs well in terms of load balancing and stability.Experiments have shown that the combination of structured network and trusted execution environment provides better throughput and latency.Its efficiency is at least twice that of Min BFT,and the performance advantage is more obvious as the number of replicas increases.