Cryptology ePrint Archive: Report 2017/406

OmniLedger: A Secure, Scale-Out, Decentralized Ledger

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

Abstract: Designing a secure and open Distributed Ledger (DL) system that performs on par with classic payment-service providers such as Visa is a challenging task. Current proposals either do not scale-out or do so only at the cost of security or decentralization. OmniLedger is a new scalable DL that provides secure, decentralized, horizontal scaling by splitting the state into multiple shards and using distributed randomness to assign validators securely. To maintain intra- and cross-shard consistency validators run a novel parallel consensus algorithm for the former and an Atomic Commit protocol for the latter. To mitigate storage cost and enable fast, secure bootstrapping, OmniLedger introduces compact state-blocks that summarize shard-states.

OmniLedger offers tunable performance based on the assumed strength of the adversaries, and scales linearly with the number of shards. Experiments show that it achieves Visa-level throughput of 6000 transactions per second (peaking at 50000) for 1800 validators, of which up to 12.5% (5%) are assumed to be malicious. Finally, OmniLedger significantly reduces bandwidth cost for out-of-date validators to update: for a one-month-old view, a validator downloads 40% of the amount of data compared to Bitcoin, whereas a new validator downloads only 7% while bootstrapping.

Category / Keywords: applications / Blockchains, Scale-Out, Decentralization

Date: received 11 May 2017

Contact author: eleftherios kokoriskogias at epfl ch

Available format(s): PDF | BibTeX Citation

Version: 20170511:122303 (All versions of this report)

Short URL: ia.cr/2017/406

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