Cryptology ePrint Archive: Report 2017/406

OmniLedger: A Secure, Scale-Out, Decentralized Ledger via Sharding

Eleftherios Kokoris-Kogias and Philipp Jovanovic and Linus Gasser and Nicolas Gailly and Ewa Syta and Bryan Ford

Abstract: Designing a secure permissionless distributed ledger that performs on par with centralized payment processors such as Visa is challenging. Most existing distributed ledgers are unable to "scale-out'' -- growing total processing capacity with number of participants -- and those that do compromise security or decentralization. This work presents OmniLedger, the first scale-out distributed ledger that can preserve long-term security under permissionless operation. OmniLedger ensures strong correctness and security by using a bias-resistant public randomness protocol to choose large statistically representative shards to process transactions, and by introducing an efficient cross-shard commit protocol to handle transactions affecting multiple shards atomically. In addition, OmniLedger optimizes performance via scalable intra-shard parallel transaction processing, ledger pruning via collectively-signed state blocks, and optional low-latency "trust-but-verify'' validation of low-value transactions. Evaluation of our working experimental prototype shows that OmniLedger's throughput scales linearly in the number of validators available, supporting Visa-level workloads and beyond, while confirming typical transactions in under two seconds.

Category / Keywords: Blockchains, Scale-Out, Decentralization, Sharding, High throughput, Low latency, Trust-but-Verify

Original Publication (in the same form): 39th IEEE Symposium on Security and Privacy

Date: received 11 May 2017, last revised 21 Feb 2018

Contact author: eleftherios kokoriskogias at epfl ch

Available format(s): PDF | BibTeX Citation

Version: 20180221:204954 (All versions of this report)

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