Systematizing Decentralization and Privacy: Lessons from 15 Years of Research and Deployments
It addresses the challenge of building scalable and privacy-preserving decentralized systems for designers and researchers, but is incremental as it synthesizes existing knowledge.
The paper reviews 15 years of research on decentralized systems to tackle the problem of balancing privacy, integrity, and availability with system complexity and decentralization trade-offs, resulting in key insights and design guidelines for future systems.
Decentralized systems are a subset of distributed systems where multiple authorities control different components and no authority is fully trusted by all. This implies that any component in a decentralized system is potentially adversarial. We revise fifteen years of research on decentralization and privacy, and provide an overview of key systems, as well as key insights for designers of future systems. We show that decentralized designs can enhance privacy, integrity, and availability but also require careful trade-offs in terms of system complexity, properties provided, and degree of decentralization. These trade-offs need to be understood and navigated by designers. We argue that a combination of insights from cryptography, distributed systems, and mechanism design, aligned with the development of adequate incentives, are necessary to build scalable and successful privacy-preserving decentralized systems.