Investigate XMR-BTC atomic cross chain swap protocol options

[chimp1984]

This is a Bisq Network project. Please familiarize yourself with the project management process.

Description

Research for figuring out feasibility and best architecture for integration XMR-BTC atomic cross chain swaps.
There are 2 projects which have implemented it:

• https://github.com/farcaster-project (funded by the XMR community, they worked since several years on that problem and have a deep cryptographic background)
• https://github.com/comit-network/xmr-btc-swap (startup prototyping several swaps like ETH, Grin, XMR, now working on Liquid covenants).

Rationale

Atomic cross chain swaps are a very exciting development and as it is now technically possible to do it for XMR-BTC by using the approach utilizing adapter signatures and as XMR is the main market of Bisq we should investigate feasibility for that option.
With the new BSQ/BTC atomic swaps we have now a second trade protocol integrated and the learning could be re-used for adding yet another protocol.
The targeted integration is considering Bisq as a client talking to the swap daemon as well as providing the offer book functionality. The actual protocol execution, cryptographic and blockchain related tasks are done inside their infrastructure which is running locally or on a user controlled server. It likely requires a full XMR node, a full BTC node and the swap daemon.

Criteria for delivery

A summary of the findings and plan how it can be integrated should be delivered.

Measures of success

Get a basic understanding about the state of the 2 projects. Get a swap running locally (not needed for both, just with the favorite). Get a rough plan how it can be integrated with Bisq.

Risks

The scope of that investigation should be time limited to 3 weeks so that in case no result has been found the risk for lost effort is limited.

Tasks

• Check out the status of the 2 projects
• Decide on which one to focus on and get in touch with the dev team to learn about their commitment to help with support in case it is used in production
• Get a swap executed in local environment
• Figure out the best way how the infrastructure could be integrated with Bisq (e.g. RPC API)
• Figure out how Tor can be used for the network layer at the swap handshakes

Estimates

TBD from devs who commit to the tasks

Notes

In today's dev call (15.10) we discussed this idea and @jmacxx and @sqrrm signaled interest to work on that project.
I can be part of it as well, but prefer to focus on the Bisq side.