Topology-Matched P2P Broadcasting Protocol: A Collaborative Optimization Solution for Blockchain CAP Trilemma

Abstract

The classical CAP theorem reveals fundamental limitations in distributed system design, namely the impossibility of simultaneously achieving strong Consistency, high Availability, and Partition tolerance. As an important distributed ledger technology, blockchain systems also face these constraints. Recent research has attempted to alleviate this problem through consensus layer or physical layer optimization techniques. However, these methods fail to achieve optimal availability due to the mismatch problem between network layer and physical layer topologies. Therefore, this paper designs a P2P broadcasting protocol that matches physical topology structures at the network layer, namely Matching-Gossip, serving as an intelligent adapter between physical topology and consensus protocols to collectively address the CAP trilemma. Experimental results demonstrate that blockchain systems based on Matching-Gossip achieve trilemma efficiency coefficients exceeding 95%, simultaneously meeting engineering requirements for strong consistency, high availability, and partition tolerance, thereby breaking through traditional CAP limitations on blockchain system design.