{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,6]],"date-time":"2026-05-06T04:15:40Z","timestamp":1778040940008,"version":"3.51.4"},"reference-count":45,"publisher":"International Association for Cryptologic Research","issue":"1","license":[{"start":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T00:00:00Z","timestamp":1769990400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IACR CiC"],"accepted":{"date-parts":[[2026,4,15]]},"abstract":"<jats:p>Atomic swaps allow two parties to exchange coins across blockchains without trust. Most existing solutions support a 1-to-1 transaction; however, the value ratio of two cryptocurrencies is usually not 1-to-1. In addition, these solutions often rely on blockchains with explicit support structures for atomic swaps, typically hashed timelocks (HTLCs) or smart-contract scripting. Thyagarajan et al.\u00a0(SP'22) provide a solution for n-to-m swaps utilizing adaptor signatures instead, which offer better privacy for the participants. Significantly, all these approaches need timed transactions or a similar substitute on both sides, but not every blockchain supports timed transactions. Hoenisch et al.\u00a0(ESORICS'22) demonstrate a concrete swap procedure between Bitcoin and Monero, where only one side needs timed transactions. We build upon both of these ideas to provide a generic solution for any blockchain, where only one side needs timed transactions.<\/jats:p>\n                  <jats:p>We introduce a generic adaptor-signature protocol for n-to-m swaps. In doing so, we minimize assumptions compared to current solutions. Both sides lock their coins in shared (two-party signature) addresses, where they can only access the coins together. To prevent deadlocks, both parties are able to refund their coins from these addresses with pre-signed transactions. Our solution works with all relevant blockchains because it needs only standard signatures and a joint public key. Further, only one side needs timed transactions, and if each party acts in its best interest, there are two possible outcomes: If progress stalls, the side with timelocks refunds after a certain time, and the other side refunds immediately. Otherwise, one party redeems the other party's coins with pre-signed transactions, and the other party completes the swap after a timeout to prevent race conditions. We prove security in the universal composability framework and show privacy preservation via unlinkability and fungibility.<\/jats:p>","DOI":"10.62056\/abe0ivol7","type":"journal-article","created":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T18:09:08Z","timestamp":1777918148000},"update-policy":"https:\/\/doi.org\/10.62056\/adfjwm02dj","source":"Crossref","is-referenced-by-count":0,"title":["Atomic Swaps with Relaxed Assumptions"],"prefix":"10.62056","volume":"3","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2324-5671","authenticated-orcid":false,"given":"Paul","family":"R\u00f6sler","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/00f7hpc57","id-type":"ROR","asserted-by":"publisher"}],"name":"Friedrich-Alexander-Universit\u00e4t Erlangen-N\u00fcrnberg","place":["Erlangen, 91054, Germany"],"department":["Chair of Applied Cryptography"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Katharina","family":"Schambach","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/00f7hpc57","id-type":"ROR","asserted-by":"publisher"}],"name":"Friedrich-Alexander-Universit\u00e4t Erlangen-N\u00fcrnberg","place":["Erlangen, 91054, Germany"],"department":["Chair of Applied Cryptography"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-9033-0449","authenticated-orcid":false,"given":"Julian","family":"Thomas","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/00f7hpc57","id-type":"ROR","asserted-by":"publisher"}],"name":"Friedrich-Alexander-Universit\u00e4t Erlangen-N\u00fcrnberg","place":["Erlangen, 91054, Germany"],"department":["Chair of Applied Cryptography"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"48349","published-online":{"date-parts":[[2026,5,4]]},"reference":[{"key":"ref1:X9.62","volume-title":"ANSI X9.62 Public Key Cryptography for the Financial\n  Services Industry: the Elliptic Curve Digital Signature Algorithm (ECDSA)","author":"Inc. 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