Assignment: Trade protocol analysis, design and implementation

[HenrikJannsen]

This assignment is give to candidates who want to join Bisq in response to the recent blog post and job offer listings. It is open to anyone who want to become a Bisq 2 developer, though it is not mandatory.

Getting Started

The first step is to explore the Bisq 2 repository, set up a local environment with a seed node and two trade apps (we use IntelliJ as our IDE), and become familiar with the codebase and use cases.

Documentation may occasionally be outdated due to frequent changes. If you encounter issues, report them or, better yet, submit a pull request to improve them.

We expect senior Java developers to be capable of setting up the project independently. Problem-solving in an imperfect environment is part of the challenge of working with Bisq—and improving those deficiencies is always welcome.

Assignment

We assign all candidates the same non-trivial challenge, which involves analysis, design, and implementation.

Improve the Trade Protocol Framework

Bisq uses a simple, restricted state machine to manage its trade protocol. This protocol determines which actions should be performed based on specific events and messages, ensuring trade security.

We have already developed such a framework for the Bisq Easy trade protocol, and we are now looking to analyze, refine, or improve it to accommodate the more complex MuSig protocol—and, in the future, potentially even more advanced protocols like Bisq Lightning.

More details can be found in the GitHub discussion.

Analysis Phase

• Familiarize yourself with the MuSig protocol to understand its challenges (e.g., multiple unhappy paths). Deep cryptographic knowledge is not required—just an understanding of the different steps and paths the protocol must implement.
• Analyze the current model for potential issues (beyond those already noted in the discussion).
• Provide your feedback; based on your analysis, we will decide on the next steps.

Design Phase

• If you propose alternatives to the state machine model, outline your reasoning and provide a design and basic implementation for a mock protocol covering both the Bisq Easy and MuSig requirements.
• If you believe the state machine model is the best approach, suggest ways to enhance its robustness and flexibility (especially for future protocol updates).
• Provide feedback; based on this, we will determine how to proceed.

Proof of Concept Implementation

• Implement your proposed design as a proof of concept.
• If your solution is selected for MuSig, the next step will be full implementation.

Production Implementation

• Develop a production-quality implementation of MuSig.
• Evaluate whether to replace the Bisq Easy protocol with the new one (if backward compatibility permits). If not, consider a rollout strategy for a non-backward-compatible update or leave Bisq Easy unchanged.

Compensation & Expectations

If any of your work is integrated into Bisq, it will be eligible for compensation via the Bisq DAO. However, please note that while there is no guaranteed payment from the Bisq DAO, reasonable requests have historically been approved without conflicts.

We acknowledge that this assignment is more substantial than a typical job interview task (which, in the age of AI, may no longer be that meaningful). We also recognize that Bisq may benefit from various analyses and design suggestions, even if they are not ultimately adopted.

To avoid conflicts, please clarify upfront if you expect payment for any step of the process. We will assess whether we can offer compensation (e.g., as a bounty) based on your qualifications.

[RipleyCipher]

I'm currently reviewing the information available on MuSig and I am wondering if the implementation you are looking to do is based on MuSig or MuSig2. can anyone clarify this for me?

[ChrisSon15]

Hi, its based on MuSig2. I see MuSig2 as a replacement for MuSig version 1. I know, that in some articles we just wrote MuSig, but really meant MuSig2, that was just out of lazyness. Sorry for the confusion.