Thunderella: Blockchains with Optimistic Instant Confirmation
Elaine Shi
Abstract:
Classical consensus protocols have been widely deployed by companies such as Google and Facebook to replicate their computing infrastructure --- although traditional deployments are usually in controlled and small-scale environments. The rise of cryptocurrencies has stimulated excitement in large-scale deployments of distributed consensus, e.g., across thousands of nodes and hundreds of (possibly mutually distrustful) organizations. Thus the race is on for industry consortia, companies, and academia alike to create and implement large-scale consensus protocols that are ever more robust and ever more scalable.
In this talk, we ask what should be the "dream" protocol for large-scale distributed consensus. Towards exploring this question, we propose a new paradigm called Thunderella. Thunderella has the simplicity and robustness of a blockchain protocol, but in the optimistic case confirms transaction in 2-3 actual network rounds without having to wait for even a single "block interval". Our paradigm can be instantiated in both permissioned and permissionless settings and we believe that the protocol's marked simplicity will facilitate implementation, reconfiguration, and operational maintenance in large-scale deployments.
Joint work with Rafael Pass.