Node-Based Blockchain Decentralization Measurement Model

Blockchain decentralization refers to the characteristics of blockchain systems in which data storage, transaction verification, and ledger state updates are performed and maintained by distributed nodes, rather than relying on the servers of centralized institutions or organizational entities. It is one of the core features of blockchain systems to ensure security, anti-censorship, and system robustness. Quantifying the degree of blockchain decentralization helps identify potential centralization risks and evaluate the fairness of system architectures and governance mechanisms, and provides an important basis for the optimization design for improving consensus efficiency and resource allocation, as well as for evaluating the credibility and understanding the future development trends of blockchain systems in terms of scalability, application domains, and regulatory adaptability. Existing blockchain decentralization measurement methods rely on one or two dimensions, ignore trend analysis of the degree of decentralization, and lack standardized quantitative approaches, such as the consistent application of methods like the coefficient of variation or the information entropy, to enable objective and comparable assessments across different systems. Given that blockchain systems are composed of participating nodes, we adopt a node-centric perspective, and propose a Node-based Blockchain Decentralization Measurement Model (NBDMM). NBDMM uses ten key indicators extracted from three dimensions, node distribution, transaction-network centralization, and node reliability, to measure the degree of decentralization. Experimental results demonstrate that the proposed NBDMM effectively quantifies the level of decentralization across blockchain systems with varying consensus mechanisms. Moreover, findings indicate a trend toward increasing centralization in both Bitcoin and Ethereum, suggesting a gradual erosion of their originally decentralized nature.