HashVer: Low-Latency Consensus on Blockchain Networks With Heterogeneous Nodes

Abstract

Blockchain can enhance the security of networks and enable high-quality collaborations among distributed nodes. But meanwhile, its consensus process introduces additional message interactions and verifications into the network. The resource-constrained nodes create bottlenecks in the multi-hop message propagation and result in high consensus latency, which limits the applications of blockchain in real-time data sharing scenarios, such as Internet of Vehicles and Industrial Internets. In view of this challenge, this paper proposes a message synchronization approach called HashVer to enable low-latency and flexible consensus on blockchain networks with heterogeneous nodes. For the lightweight nodes with limited resources, HashVer introduces a Merkle tree-based branch verification that allows nodes to check a random sample of transactions in a block efficiently. This allocates the resource-intensive verification task to different nodes and enables a demand-oriented transaction synchronization. For the full nodes with sufficient resources, HashVer introduces a transaction synchronization approach that fully utilizes the bandwidth resource to synchronize the possible content and order of transactions in the next block. Then, a Merkle root match is utilized to recover the transactions in a block with low latency. We evaluate the performance and security of HashVer through theoretical modeling and performance comparisons. The results show that HashVer can effectively reduce the consensus latency while saving the bandwidth resources of lightweight nodes.