Re: [bitcoin-dev] Post-mix(coinjoin) usage with multisig and cpfp in bitcoin core wallet

[ZmnSCPxj <ZmnSCPxj@protonmail.com>]

Good morning Prayank

> I have explained the whole idea with a proof of concept in this link: https://medium.com/@prayankgahlot/post-mix-usage-using-multisig-and-cpfp-e6ce1fdd57a1

The article is not clear I think, so please confirm my understanding below.

Participants:

* "Peer 3" - Payee
* "Peer 2" - Payer
* "Peer 1" - Enabling tr\*sted third party

Goal: Payer wants to pay to the payee 0.006BTC

Current Conditions:

* Payer owns 0.01 BTC in a single UTXO
* Third Party owns 0.05 BTC in a single UTXO

Protocol:

1.  Payer and Third Party compute a 2-of-3 address with the public keys of Payer, Payee, and Third Party.
2.  Payer and Third Party individually pay their owned funds to the 2-of-3 address.
3.  After confirmation, they consume the new outputs into another transaction with equal-valued outputs, hiding who owns which coins.

Is my understanding correct?

If so, I believe JoinMarket has a superior technology, which does not require a tr\*sted third party; it simply requires one or more UNtrusted third parties to participate in signing a single transaction that does not require paying to an intermediate m-of-n address (thus all inputs are singlesig).

Basically JoinMarket allows the market taker to decide how much the equal-value outputs are, and to define the address it goes to.
The destination address need not be one the market taker controls, it can be to a payee.
This technique is the only out-of-the-box way that a JoinMarket wallet can spend funds from a JoinMarket wallet.

JoinMarket as well already includes how to get in touch with enabling third parties (called "market makers").


Regards,
ZmnSCPxj