Dynamic Membership Management for a Permissioned Blockchain

Managing membership is a significant challenge in permissioned blockchains to ensure their liveness and safety. Current blockchain systems utilize a consensus protocol that can withstand malicious actors, necessitating a communication-heavy Byzantine fault tolerant (BFT) consensus protocol that is unnecessary in normal-case operations. Furthermore, prior consensus protocols assume a scale of nodes in orders of magnitude higher than is valuable for a permissioned blockchain. Additionally, permissioned blockchains such as Ripple [1] lack an algorithmic structure for membership management, compromising their decentralization. We present a novel and equitable membership protocol design tailored for lightweight consensus mechanisms to address these limitations. Our self-regulating protocol dynamically adjusts the permissioned node set per consensus round, responds to network anomalies, and maintains byzantine fault tolerance. Our membership protocol provides a loose coupling of resilience from the consensus protocol, which can be coupled with an elementary consensus protocol, making it a promising solution for managing membership in permissioned blockchains.