Visible to the public PolyShard: Coded Sharding Achieves Linearly Scaling Efficiency and Security Simultaneously

TitlePolyShard: Coded Sharding Achieves Linearly Scaling Efficiency and Security Simultaneously
Publication TypeConference Paper
Year of Publication2020
AuthorsLi, S., Yu, M., Yang, C.-S., Avestimehr, A. S., Kannan, S., Viswanath, P.
Conference Name2020 IEEE International Symposium on Information Theory (ISIT)
Keywordsblockchain designs, blockchain system, coded sharding, coded storage protocol, coding theory, compositionality, cryptography, decentralization scalability, Information theory, information-theoretic upper bounds, linear codes, linearly scaling efficiency, Metrics, node subsets, performance scalability, polynomially coded sharding, polynomials, PolyShard, Protocols, pubcrawl, resilience, Resiliency, security, security of data, security scalability, sharding proposals, storage efficiency, system throughput, truly scalable system, trust-corrupting
AbstractToday's blockchain designs suffer from a trilemma claiming that no blockchain system can simultaneously achieve decentralization, security, and performance scalability. For current blockchain systems, as more nodes join the network, the efficiency of the system (computation, communication, and storage) stays constant at best. A leading idea for enabling blockchains to scale efficiency is the notion of sharding: different subsets of nodes handle different portions of the blockchain, thereby reducing the load for each individual node. However, existing sharding proposals achieve efficiency scaling by compromising on trust - corrupting the nodes in a given shard will lead to the permanent loss of the corresponding portion of data. In this paper, we settle the trilemma by demonstrating a new protocol for coded storage and computation in blockchains. In particular, we propose PolyShard: "polynomially coded sharding" scheme that achieves information-theoretic upper bounds on the efficiency of the storage, system throughput, as well as on trust, thus enabling a truly scalable system.
Citation Keyli_polyshard_2020