From Concept to Measurement: A Survey of How the Blockchain Trilemma Is Analyzed

The blockchain trilemma highlights the difficulty of simultaneously achieving a high degree of decentralization (DoD), scalability, and security in blockchain systems. While numerous constructs and metrics have been proposed to analyze these subconcepts, existing guidance is fragmented and inconsistent, limiting comparability across studies. This lack of clarity hinders practitioners in identifying Pareto-optimal blockchain system designs that meet common non-functional requirements. We systematically reviewed literature on the blockchain trilemma and blockchain benchmarks to synthesize constructs and their operationalizations through metrics to analyze the trilemma's subconcepts. We identified 12 constructs, operationalized through 15 metrics, that capture DoD, scalability, and security. We explain how these constructs apply across different blockchain systems and provide a structured overview that supports benchmarking and blockchain system design. Beyond blockchain, the findings offer insights for distributed database systems that rely on consensus and state machine replication. This work contributes a harmonized foundation for quantitative analyses of the blockchain trilemma, guiding both researchers in developing analysis approaches and practitioners in evaluating real-world systems.