Full TitleSMaRtChain - Fast and Energy-efficient Distributed Consensus for Blockchains
Fuelled by the success of Bitcoin and other cryptocurrencies, blockchain has emerged as a paradigm for building secure decentralised applications that will revolutionise many aspects of our digital life. After an initial period of hype, blockchain technology is now cementing itself in many important societal domains. From NFTs being used to track ownership of both virtual and physical artefacts, to DeFi organisations ruled by smart contracts, blockchain technologies are required by most financial, government, notary, and supply-chain services. It is hard to find an online application that could not benefit from a secure programmable transaction ledger with no central point of trust/failure. However, there are still many challenges that remain to be addressed to fulfil the blockchain promises. These issues are mostly related to existing protocols’ low performance, high energy consumption, lack of finality (i.e., committed transactions can be reversed), and the weakness or poor understanding of its security assumptions. In the last five years, several works have been addressing these limitations, but their impact on new blockchain offerings is still to be seen.
This project – SMaRtChain – aims to address critical limitations of existing blockchains by exploiting a set of promising principles and models that have been mostly unexplored in the blockchain and Byzantine Fault Tolerance (BFT) research literature. We will devise new consensus protocols for improving both consortium/permissioned blockchains – where the group of nodes maintaining the blockchain is restricted and known, as in Hyperledger Fabric and Tendermint; and open/permissionless blockchains – where the group of nodes maintaining the blockchain is open and unknown, as in Bitcoin and Ethereum. Amongst other contributions, we will explore new probabilistic constructions to devise scalable low-latency BFT consensus protocols, which are particularly interesting in the context of permissioned blockchains, and also important for certain permissionless networks; and we plan to extend the theoretical underpinnings of the Consensus with Unknown Participants model, which is relevant for devising robust energy-efficient permissionless blockchains. Investigating these ideas will lead to contributions both to distributed computing theory and experimental systems research. In the end, we expect to produce an experimental opensource blockchain platform and some representative applications.