Hyperledger Mentorship Spotlight: Fabric-Ethereum token bridging

What did you work on?

Project name: Fabric-Ethereum token bridging

Main objectives:

1. Review cross-chain bridges state of the art.
2. Study and develop chaincode and smart contracts following ERC standards.
3. Prototype a cross-chain bridge between Hyperledger Fabric and EVM-based blockchains. Hyperledger Technologies: Hyperledger Fabric, Hyperledger Besu, Hyperledger Cactus.

Mentors:

1. Imre Kocsis, assistant professor, Budapest University of Technology and Economics (BME), Budapest, Hungary.
2. László Gönczy, assistant professor, Budapest University of Technology and Economics (BME), Budapest, Hungary.

Impact yielded from work:

This work constitutes an add-on to the existing efforts to enable interoperability between permissioned networks. Moreover, we contribute to the community by developing a cross-chain bridge between Hyperledger Fabric and EVM-based blockchains using the Secure Asset Transfer Protocol (SATP), a protocol under standardization at the Internet Engineering Task Force (IETF).

What did you learn or accomplish?

Deliverables:

1. Create a report on blockchain interoperability solutions.
2. Design a cross-chain bridge between a Hyperledger Fabric and a Hyperledger Besu network.
3. Implement a prototype of the designed cross-chain bridge solution in Hyperledger Cactus.
4. Develop an academic paper.

Issues overcome:

1. At the beginning there were a lot of unknowns: a new area, protocols, and new technology. After all, I am glad about the final product and all the lessons learned.

Lessons learned and advice:

1. The community is here to help. We had fruitful discussions with various members of the Hyperledger community, which proved to be valuable for the final project.
2. The best is always yet to come. Believe me when I say things will always be better than they are at the moment — bugs appear, and sometimes we need to take a step back to take two steps forward.

Exciting technology:

1. Hyperledger Fabric was considered the most adopted enterprise blockchain solution.
2. Hyperledger Cactus provides the building blocks for interoperability.
3. The integration of Self-Sovereign Identity (SSI) with interoperability solutions seems to be the way forward to perform identity management.

What comes next?

• The addition of SSI in our work seems a good next step as a way to remove some assumptions made in the solution design.
• I envision to continue working and advancing the existing interoperability research. I aim to continue contributing to Hyperledger Cactus (now Hyperledger Cacti), the Hyperledger project directed toward interoperability.