
Briefing
The core research problem in distributed systems involves achieving robust consensus without a centralized leader or high resource consumption, a limitation inherent in protocols like PBFT and Proof-of-Work. This paper introduces the Blockchain Epidemic Consensus Protocol (BECP), a fully decentralized, leaderless system that leverages randomized epidemic communication and lightweight local computation to achieve agreement. This new mechanism enables a paradigm shift toward truly extreme-scale blockchain architectures by offering outstanding scalability and fast, logarithmic convergence without reliance on a fixed validator set or high resource demands.

Context
The established theory of Byzantine Fault Tolerance (BFT) protocols, including classic PBFT, Raft, and Paxos, requires a designated leader, which creates a single point of failure and a systemic bottleneck for throughput. Resource-intensive Proof-of-Work (PoW) is environmentally costly, and Proof-of-Stake (PoS) introduces risks of stake centralization and collusion, compromising decentralization at scale. A foundational challenge remained in designing a protocol for open, public networks that is truly leaderless, resource-efficient, and capable of scaling to thousands of nodes with low latency.

Analysis
BECP’s core mechanism is a leaderless consensus model that integrates three sub-protocols ∞ a System Size Estimation Protocol (SSEP), a Node Cache Protocol (NCP), and a modified Phase Transition Protocol (PTP). Unlike previous epidemic-based systems that rely on repeated K-neighbor sampling and inquiry, BECP achieves consensus through continuous, randomized “gossiping” where nodes send information to only one random neighbor. The foundational breakthrough is the block resolution procedure, which allows nodes to generate new blocks without waiting for the confirmation of the last block. By tracking a “preferred block” (Bpref) and utilizing local computation to resolve duplicate blocks, the protocol guarantees a consistent chain while significantly boosting throughput and minimizing network overhead.

Parameters
- Consensus Latency Improvement ∞ 4.775 times better average consensus latency compared to the Avalanche protocol.
- Throughput Increase ∞ 1.196 times higher throughput compared to the Avalanche protocol.
- Node Scalability Tested ∞ 500 to 5000 nodes, demonstrating favorable scaling properties.
- Communication Mechanism ∞ Nodes send messages to only one random neighbor, significantly reducing network overhead.

Outlook
The BECP protocol establishes a new paradigm for fully decentralized, leaderless consensus, opening up research avenues in extreme-scale distributed systems and resource-constrained environments like IoT networks where massive node counts are critical. Future research will focus on augmenting BECP to include mechanisms for detecting node failures and triggering a recovery process, further enhancing system resilience and fault tolerance in dynamic, open networks. This model represents a key architectural building block for future decentralized infrastructure.

Verdict
The Blockchain Epidemic Consensus Protocol fundamentally re-architects decentralized agreement by replacing centralized trust and computational expense with a highly scalable, leaderless, and provably efficient randomized communication model.
