SEKad: a scalable protocol for blockchain networks with enhanced broadcast efficiency

Blockchain technology has been increasingly integrated into various fields of economic and social development. However, scalability issues such as low broadcast efficiency, high communication overhead, and high redundant transmission rate have greatly limited the large-scale application of blockchain. This paper proposes a new scalability-enhanced Kademlia network protocol (SEKad), which optimizes blockchain network transmission in terms of both network topology and communication broadcast mechanism, provides a new approach to solving the scalability problem from the network layer. In SEKad protocol, firstly, SEKad employs a method that aligns the physical topology with the network topology for node clustering. This strategy groups neighboring nodes into clusters, streamlining network complexity and reducing network diameter. Secondly, SEKad presents a cluster-adaptable network topology based on Kademlia (Kad-CA). Kad-CA improves the rationality and efficiency of per-hop routing, optimizing the construction of K buckets and thus enhancing overall network efficiency. Finally, within the network transmission model, SEKad devise the smallest sub-tree broadcasting mechanism and the minimum redundant transmission mechanism for Kad-CA. These mechanisms work to reduce the redundant transmission rate, and enhance broadcasting efficiency. In order to evaluate the performance of SEKad, we built an experimental platform and conducted evaluations. The experimental results show that SEKad has better network scalability and stability, the network diameter size can be reduced by 27% and the redundant transmission rate can be reduced by 30%.