Cryptology ePrint Archive: Report 2016/871

Blockchain-Free Cryptocurrencies: A Framework for Truly Decentralised Fast Transactions

Xavier Boyen and Christopher Carr and Thomas Haines

Abstract: The "blockchain" distributed ledger pioneered by Bitcoin is effective at preventing double-spending, but inherently attracts (1) "user cartels" and (2) incompressible delays, as a result of linear verification and a winner-takes-all incentive lottery.

We propose to forgo the blocks and chain entirely, and build a truly distributed ledger system based on a lean graph of cross-verifying transactions, which now become the main and only objects in the system. A fully distributed consensus mechanism, based on progressive proofs of work with predictable incentives, ensures rapid convergence even across a large network of unequal participants, who all get rewards working at their own pace. Graph-based affirmation fosters snappy response through automatic scaling, while application-agnostic design supports all modern cryptocurrency features such as multiple denominations, swaps, securitisation, scripting, smart contracts, etc.

We prove theoretically, and experimentally verify, our proposal to show it achieves a crucial "convergence" property, meaning that any valid transaction entering the system will quickly become enshrined into the ancestry upon which all future transactions will rest.

Category / Keywords: Decentralised, Collaborative, Bitcoin, Distributed Ledger, Cryptocurrency, Digital currency, Blockchain

Date: received 6 Sep 2016, last revised 13 Mar 2017

Contact author: ccarr at ntnu no

Available format(s): PDF | BibTeX Citation

Version: 20170313:122005 (All versions of this report)

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