Cryptology ePrint Archive: Report 2020/024

The Arwen Trading Protocols (Full Version)

Ethan Heilman and Sebastien Lipmann and Sharon Goldberg

Abstract: The Arwen Trading Protocols are layer-two blockchain protocols for traders to securely trade cryptocurrencies at a centralized exchange, without ceding custody of their coins to the exchange. Before trading begins, traders deposit their coins in an on-blockchain escrow where the agent of escrow is the blockchain itself. Each trade is backed by the coins locked in escrow. Each trade is fast, because it happens off-blockchain, and secure, because atomic swaps prevent even a hacked exchange from taking custody of a trader’s coins. Arwen is designed to work even with the "lowest common denominator" of blockchains—namely Bitcoin-derived coins without SegWit support. As a result, Arwen supports essentially all "Bitcoin-derived" coins e.g., BTC, LTC, BCH, ZEC, as well as Ethereum. Our protocols support Limit and RFQ order types, we implemented our RFQ protocol and are available for use at

Category / Keywords: cryptographic protocols / fair exchange, cryptographic protocols, cryptocurrencies

Original Publication (with major differences): Financial Cryptography and Data Security 2020

Date: received 7 Jan 2020

Contact author: ethan at arwen io

Available format(s): PDF | BibTeX Citation

Version: 20200109:145425 (All versions of this report)

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