Deconstructing the Decentralization Trilemma
This work addresses challenges in designing decentralized systems for blockchain and peer-to-peer applications, but it is incremental as it builds on existing threat models and typologies.
The paper tackles the trilemma between security, scalability, and decentralization in blockchain-based systems by defining a typology of centralized, federated, and decentralized architectures, and outlines seven hard problems facing decentralization.
The vast majority of applications at this moment rely on centralized servers to relay messages between clients, where these servers are considered trusted third-parties. With the rise of blockchain technologies over the last few years, there has been a move away from both centralized servers and traditional federated models to more decentralized peer-to-peer alternatives. However, there appears to be a trilemma between security, scalability, and decentralization in blockchain-based systems. Deconstructing this trilemma using well-known threat models, we define a typology of centralized, federated, and decentralized architectures. Each of the different architectures has this trilemma play out differently. Facing a possible decentralized future, we outline seven hard problems facing decentralization and theorize that the differences between centralized, federated, and decentralized architectures depend on differing social interpretations of trust.