We are pleased to invite you to the defence of Fjölnir Þrastarson. Please join us to explore the research and findings during this important academic event. Your support and participation would be greatly appreciated.

Abstract

Managing membership is a significant challenge in permissioned blockchains to ensure their liveness and safety. Current blockchain systems utilize a consensus mechanism designed to withstand malicious actors, which necessitates the implementation of a Byzantine fault-tolerant consensus protocol. This protocol, in turn, requires a communication-heavy or resource-intensive approach for proposing blocks. Furthermore, prior consensus protocols assume a scale of nodes in orders of magnitude higher than may be valuable for permissioned blockchains. To address these limitations, we present a design of a novel and equitable membership management protocol design and modifications to a lightweight block consensus protocol that assumes a round- dependent set of permissioned and byzantine nodes in a full-mesh peer-to-peer net- work. With n >= 3f + 1 nodes, our self-regulating membership protocol tolerates up to f faulty nodes and provides a loose decoupling of the resilience from the block con- sensus protocol. As a result, an elementary block consensus protocol can be used with our membership protocol, making it a promising solution for managing membership in permissioned blockchains for use cases with a limited writer set, infrequent failures, and write-heavy use cases.

Defence committee

Main Supervisor: 

• Gísli Hjálmtýsson, Professor, Reykjavik University.

Committee members:

• Anna Sigríður Íslind, Associate Professor, Reykjavik University. 
• Marcel Kyas, Assistant Professor, Reykjavik University.