CoinSwap - Revision history

Calliptamus: /* History */

2025-05-04T18:24:07Z

History

← Older revision		Revision as of 18:24, 4 May 2025
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	CoinSwap was first proposed by Greg Maxwell in October 2013.<ref>[https://bitcointalk.org/index.php?topic=321228.0 CoinSwap: Transaction graph disjoint trustless trading]</ref>. In February 2022 '''MercuryWallet''' was the first CoinSwap implementation has been deployed<ref>[https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2020-May/017898.html Design for a CoinSwap implementation for massively improving Bitcoin privacy and fungibility]</ref><ref>[https://gist.github.com/chris-belcher/9144bd57a91c194e332fb5ca371d0964 Coinswap design document]</ref>. In June 2020, the [https://en.wikipedia.org/wiki/Human_Rights_Foundation Human Rights Foundation] (a New York-based nonprofit that promotes and protects human rights globally) granted $50,000 to [https://en.bitcoin.it/wiki/User:Belcher Chris Belcher] (one of the main contributors to the [[Privacy]] page) to work on the project.<ref>[https://bitcoinmagazine.com/articles/the-human-rights-foundation-is-now-funding-bitcoin-privacy-development-starting-with-coinswap The Human Rights Foundation Is Now Funding Bitcoin Privacy Development, Starting With CoinSwap]</ref>		CoinSwap was first proposed by Greg Maxwell in October 2013.<ref>[https://bitcointalk.org/index.php?topic=321228.0 CoinSwap: Transaction graph disjoint trustless trading]</ref>. In February 2022 '''MercuryWallet''' was the first CoinSwap implementation has been deployed<ref>[https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2020-May/017898.html Design for a CoinSwap implementation for massively improving Bitcoin privacy and fungibility]</ref><ref>[https://gist.github.com/chris-belcher/9144bd57a91c194e332fb5ca371d0964 Coinswap design document]</ref>. In June 2020, the [https://en.wikipedia.org/wiki/Human_Rights_Foundation Human Rights Foundation] (a New York-based nonprofit that promotes and protects human rights globally) granted $50,000 to [https://en.bitcoin.it/wiki/User:Belcher Chris Belcher] (one of the main contributors to the [[Privacy]] page) to work on the project.<ref>[https://bitcoinmagazine.com/articles/the-human-rights-foundation-is-now-funding-bitcoin-privacy-development-starting-with-coinswap The Human Rights Foundation Is Now Funding Bitcoin Privacy Development, Starting With CoinSwap]</ref>

			== Comparison with CoinJoin ==

			While both CoinSwap and [[CoinJoin]] aim to enhance Bitcoin privacy, they differ fundamentally in design, trust assumptions, and on-chain footprint. Below is a breakdown of their key distinctions:

			=== Transaction structure ===

			CoinJoin: Multiple participants collaboratively create a single transaction with combined inputs and outputs. All participants sign together, and the transaction is broadcast as one entity (e.g., a 5-input, 5-output transaction).

			CoinSwap: Participants execute multiple separate transactions over time, often through intermediaries (or "hubs"), creating no direct link between their original and final UTXOs.

			=== Trust and coordination ===

			CoinJoin:

			* Requires synchronized coordination among participants (e.g., via a coordinator or software like JoinMarket).
			* Trust is minimized in non-custodial implementations, but centralized mixers may introduce custodial risk.

			CoinSwap:

			* Operates asynchronously; participants need not be online simultaneously.
			* Trust is eliminated if using atomic swaps with [[Hash Time Locked Contracts\|Hashed Time-Locked Contracts (HTLCs)]], though intermediaries (if used) could theoretically collude.

			=== Privacy guarantees ===

			CoinJoin:

			* Obscures ownership by merging funds, but advanced chain analysis may infer links via amount clustering or timing heuristics.
			* All participants’ UTXOs are visible in the same transaction graph.

			CoinSwap:

			* Breaks the direct on-chain link between sender and receiver by routing funds through unrelated transactions.
			* Resembles ordinary payments, making it harder to flag as a privacy technique.

			=== Blockchain footprint ===

			CoinJoin: Produces large, identifiable transactions with equal-output amounts (e.g., 0.1 BTC × 10), which may attract scrutiny.

			CoinSwap: Generates smaller, ordinary-looking transactions that blend with everyday Bitcoin activity.

			=== Use cases ===

			CoinJoin: Best for quickly anonymizing a batch of UTXOs with minimal fees, ideal for users prioritizing efficiency.

			CoinSwap: Suited for long-term privacy where avoiding pattern detection is critical (e.g., breaking ties between old and new UTXOs).

	== External links ==		== External links ==

Nicosey at 19:41, 23 March 2022

2022-03-23T19:41:17Z

← Older revision		Revision as of 19:41, 23 March 2022
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	* [https://joinmarket.me/blog/blog/coinswaps/ Technical explanation], July 2017		* [https://joinmarket.me/blog/blog/coinswaps/ Technical explanation], July 2017
	* [https://github.com/AdamISZ/CoinSwapCS Implementation in Python], abandoned since 2017		* [https://github.com/AdamISZ/CoinSwapCS Implementation in Python], abandoned since 2017
	* [https://mercurywallet.com Statechain & CoinSwap Wallet], February 2022		* [https://www.mercurywallet.com Statechain & CoinSwap Wallet], February 2022

	== See also ==		== See also ==

Nicosey at 19:19, 23 March 2022

2022-03-23T19:19:29Z

← Older revision		Revision as of 19:19, 23 March 2022
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	* [https://joinmarket.me/blog/blog/coinswaps/ Technical explanation], July 2017		* [https://joinmarket.me/blog/blog/coinswaps/ Technical explanation], July 2017
	* [https://github.com/AdamISZ/CoinSwapCS Implementation in Python], abandoned since 2017		* [https://github.com/AdamISZ/CoinSwapCS Implementation in Python], abandoned since 2017
	* [https://~~www.~~mercurywallet.com], Statechain & CoinSwap Wallet		* [https://mercurywallet.com Statechain & CoinSwap Wallet], February 2022

	== See also ==		== See also ==

Nicosey: /* External links */

2022-03-23T19:16:43Z

External links

← Older revision		Revision as of 19:16, 23 March 2022
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	* [https://joinmarket.me/blog/blog/coinswaps/ Technical explanation], July 2017		* [https://joinmarket.me/blog/blog/coinswaps/ Technical explanation], July 2017
	* [https://github.com/AdamISZ/CoinSwapCS Implementation in Python], abandoned since 2017		* [https://github.com/AdamISZ/CoinSwapCS Implementation in Python], abandoned since 2017
			* [https://www.mercurywallet.com], Statechain & CoinSwap Wallet

	== See also ==		== See also ==

Nicosey at 19:15, 23 March 2022

2022-03-23T19:15:25Z

← Older revision		Revision as of 19:15, 23 March 2022
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	== History ==		== History ==

	CoinSwap was first proposed by Greg Maxwell in October 2013.<ref>[https://bitcointalk.org/index.php?topic=321228.0 CoinSwap: Transaction graph disjoint trustless trading]</ref>. ~~As of May 2020, no~~ CoinSwap implementation has been deployed<ref>[https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2020-May/017898.html Design for a CoinSwap implementation for massively improving Bitcoin privacy and fungibility]</ref><ref>[https://gist.github.com/chris-belcher/9144bd57a91c194e332fb5ca371d0964 Coinswap design document]</ref>~~, but in~~ June 2020, the [https://en.wikipedia.org/wiki/Human_Rights_Foundation Human Rights Foundation] (a New York-based nonprofit that promotes and protects human rights globally) granted $50,000 to [https://en.bitcoin.it/wiki/User:Belcher Chris Belcher] (one of the main contributors to the [[Privacy]] page) to work on the project.<ref>[https://bitcoinmagazine.com/articles/the-human-rights-foundation-is-now-funding-bitcoin-privacy-development-starting-with-coinswap The Human Rights Foundation Is Now Funding Bitcoin Privacy Development, Starting With CoinSwap]</ref>		CoinSwap was first proposed by Greg Maxwell in October 2013.<ref>[https://bitcointalk.org/index.php?topic=321228.0 CoinSwap: Transaction graph disjoint trustless trading]</ref>. In February 2022 '''MercuryWallet''' was the first CoinSwap implementation has been deployed<ref>[https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2020-May/017898.html Design for a CoinSwap implementation for massively improving Bitcoin privacy and fungibility]</ref><ref>[https://gist.github.com/chris-belcher/9144bd57a91c194e332fb5ca371d0964 Coinswap design document]</ref>. In June 2020, the [https://en.wikipedia.org/wiki/Human_Rights_Foundation Human Rights Foundation] (a New York-based nonprofit that promotes and protects human rights globally) granted $50,000 to [https://en.bitcoin.it/wiki/User:Belcher Chris Belcher] (one of the main contributors to the [[Privacy]] page) to work on the project.<ref>[https://bitcoinmagazine.com/articles/the-human-rights-foundation-is-now-funding-bitcoin-privacy-development-starting-with-coinswap The Human Rights Foundation Is Now Funding Bitcoin Privacy Development, Starting With CoinSwap]</ref>

	== External links ==		== External links ==

Cryptal: Add HRF funding

2020-08-19T08:01:53Z

Add HRF funding

← Older revision		Revision as of 08:01, 19 August 2020
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	CoinSwaps require a lot of interaction between the involved parties, which can make this kind of system tricky to design while avoiding denial-of-service. They also have a liveness requirement and non-censorship requirement, meaning that the entities taking part must always be able to freely access the bitcoin network; If the internet was down for days or weeks then half-completed CoinSwaps could end with one side having their money stolen<ref>https://joinmarket.me/blog/blog/the-half-scriptless-swap/</ref>.		CoinSwaps require a lot of interaction between the involved parties, which can make this kind of system tricky to design while avoiding denial-of-service. They also have a liveness requirement and non-censorship requirement, meaning that the entities taking part must always be able to freely access the bitcoin network; If the internet was down for days or weeks then half-completed CoinSwaps could end with one side having their money stolen<ref>https://joinmarket.me/blog/blog/the-half-scriptless-swap/</ref>.

	== ~~External link~~ ==		== History ==
	~~See these links for detailed explanations of how the coinswap protocol works.~~

	* https://joinmarket.~~me/blog/blog/coinswaps/~~		CoinSwap was first proposed by Greg Maxwell in October 2013.<ref>[https://bitcointalk.org/index.php?topic=321228.0 CoinSwap: Transaction graph disjoint trustless trading]</ref>. As of May 2020, no CoinSwap implementation has been deployed<ref>[https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2020-May/017898.html Design for a CoinSwap implementation for massively improving Bitcoin privacy and fungibility]</ref><ref>[https://gist.github.com/chris-belcher/9144bd57a91c194e332fb5ca371d0964 Coinswap design document]</ref>, but in June 2020, the [https://en.wikipedia.org/wiki/Human_Rights_Foundation Human Rights Foundation] (a New York-based nonprofit that promotes and protects human rights globally) granted $50,000 to [https://en.bitcoin.it/wiki/User:Belcher Chris Belcher] (one of the main contributors to the [[Privacy]] page) to work on the project.<ref>[https://bitcoinmagazine.com/articles/the-human-rights-foundation-is-now-funding-bitcoin-privacy-development-starting-with-coinswap The Human Rights Foundation Is Now Funding Bitcoin Privacy Development, Starting With CoinSwap]</ref>
	* [https://bitcointalk.org/index.php?topic=321228.0 CoinSwap: Transaction graph disjoint trustless trading], ~~gmaxwell's original proposal~~, ~~October 30~~, ~~2013~~
	* https://github.com/AdamISZ/CoinSwapCS		== External links ==
			* [https://gist.github.com/chris-belcher/9144bd57a91c194e332fb5ca371d0964 CoinSwap implementation design document] by Chris Belcher, May 2020
			* [https://joinmarket.me/blog/blog/coinswaps/ Technical explanation], July 2017
			* [https://github.com/AdamISZ/CoinSwapCS Implementation in Python], abandoned since 2017

	== See also ==		== See also ==

Furunodo: /* External link / [https://bitcointalk.org/index.php?topic=321228.0 CoinSwap: Transaction graph disjoint trustless trading], gmaxwell's original proposal, October 30, 2013

2020-06-17T21:39:59Z

External link: * [https://bitcointalk.org/index.php?topic=321228.0 CoinSwap: Transaction graph disjoint trustless trading], gmaxwell's original proposal, October 30, 2013

← Older revision		Revision as of 21:39, 17 June 2020
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	* https://joinmarket.me/blog/blog/coinswaps/		* https://joinmarket.me/blog/blog/coinswaps/
	* https://bitcointalk.org/index.php?topic=321228.0 ~~- The~~ original proposal		* [https://bitcointalk.org/index.php?topic=321228.0 CoinSwap: Transaction graph disjoint trustless trading], gmaxwell's original proposal, October 30, 2013
	* https://github.com/AdamISZ/CoinSwapCS		* https://github.com/AdamISZ/CoinSwapCS

Furunodo: /* External link */ [dot] => .

2020-06-17T21:38:23Z

External link: [dot] => .

← Older revision		Revision as of 21:38, 17 June 2020
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	* https://joinmarket.me/blog/blog/coinswaps/		* https://joinmarket.me/blog/blog/coinswaps/
	* https://bitcointalk ~~[dot]~~ org/index.php?topic=321228.0 - The original proposal		* https://bitcointalk.org/index.php?topic=321228.0 - The original proposal
	* https://github.com/AdamISZ/CoinSwapCS		* https://github.com/AdamISZ/CoinSwapCS

Furunodo: typos, grammar, wikilink

2020-06-17T21:37:48Z

typos, grammar, wikilink

← Older revision		Revision as of 21:37, 17 June 2020
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	CoinSwap is a non-custodial privacy technique for bitcoin based on the idea of [[atomic swap]]s. If Alice and Bob want to do a coinswap; then it can be understood as Alice exchanging her bitcoin for the same amount (minus fees) of Bob's bitcoins, but done with [[Contracts\|bitcoin smart contracts]] to eliminate the ~~possiblity~~ of cheating by either side. The closely-related idea of [[atomic swap]]s has the important property of atomicity, where an exchange of blockchain tokens happens ~~eitherly~~ or not at all, there is no possibility of one side cheating the other.		'''CoinSwap''' is a non-custodial privacy technique for bitcoin based on the idea of [[atomic swap]]s. If Alice and Bob want to do a coinswap; then it can be understood as Alice exchanging her bitcoin for the same amount (minus [[miner fees\|fees]]) of Bob's bitcoins, but done with [[Contracts\|bitcoin smart contracts]] to eliminate the possibility of cheating by either side. The closely-related idea of [[atomic swap]]s has the important property of ''atomicity'', where an exchange of blockchain tokens either happens or not at all, there is no possibility of one side cheating the other.

	CoinSwaps break the transaction graph between the sent and received bitcoins. On the [[block chain]] it looks like two sets of completely disconnected transactions:		CoinSwaps break the transaction graph between the sent and received bitcoins. On the [[block chain]] it looks like two sets of completely disconnected transactions:

Belcher: Give numbers to escrow addresses so its clear they're not connected

2019-05-12T17:08:57Z

Give numbers to escrow addresses so its clear they're not connected

← Older revision		Revision as of 17:08, 12 May 2019
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	CoinSwaps break the transaction graph between the sent and received bitcoins. On the [[block chain]] it looks like two sets of completely disconnected transactions:		CoinSwaps break the transaction graph between the sent and received bitcoins. On the [[block chain]] it looks like two sets of completely disconnected transactions:

	Alice's Address ---> 2of2 multisig escrow address ---> Bob's Address		Alice's Address ---> 2of2 multisig escrow address 1 ---> Bob's Address
	Bob's Address ---> 2of2 multisig escrow address ---> Alice's Address		Bob's Address ---> 2of2 multisig escrow address 2 ---> Alice's Address

	Obviously Alice and Bob generate new [[address]]es each to avoid the privacy loss due to [[address reuse]].		Obviously Alice and Bob generate new [[address]]es each to avoid the privacy loss due to [[address reuse]].