Research on Blockchain Architecture and Operating Principles Based on H-DAG

Abstract

A hybrid blockchain structure (hybrid directed acyclic graph, or H-DAG) is proposed in this article to solve the existing problem of blockchain architectures using symmetric key encryption technology by combining the characteristics of single-chain blockchains and DAG distributed ledgers. By improving the block and transaction structures and optimizing the consensus mechanism, the H-DAG confirmed transaction orders while maintaining the high-throughput characteristics of a DAG, thus solving the transaction order dependence problem. We introduced a lightweight PoW mechanism to the H-DAG to improve the anti-fork ability of the blockchain. An incentive mechanism was adopted in our model to compel honest nodes to be more enthusiastic about participating in, maintaining, and enhancing the security of a given network. The blockchain states achieved strong levels of consistency, and their transaction confirmation times were predictable. We evaluated the performance of the H-DAG by comparing and analyzing multiple experiments, and we modeled a forking attack strategy, verifying the resistance of the H-DAG to this attack strategy. The experimental results demonstrated that the order of transactions in the H-DAG was globally consistent, and the confirmation time of transactions was predictable. The H-DAG improved the anti-fork ability and enhanced the security of the blockchain to ensure a degree of decentralization of the blockchain system. Therefore, the system throughput was enhanced by improving the block structure using symmetric key technology.