Feedback #1: More detail in the technical architecture

In order to deliver more immediate value to the Stellar Ecosystem, we changed the scope of the project to include a simpler use case that could be bring liquidity to Stellar from other ecosystems, while being compliant with the EEA specification. As a result, in the Technical Architecture Document:

• We added a simpler use case 'Buy Stellar Asset from Polygon Network' and its smart contract architecture.
• We provided more information about the more advanced use case 'Delivery versus Payment (DvP) ' and developed the content of the sequential diagram.
• We added a section with the preliminary work we did to check the compatibility and support of Soroban with the EEA Messaging Layer requirements.

Feedback #2: Who will do develop the solution

In the previous submission, we did not make it clear that the actual development work will be done by a Wanchain team members based in China. If the submission if successful, then the project will be allocated to the most appropriate developers (2 developers) at the time. The analysis work is still being done by Anais Ofranc and Weijia Zhang.

Feedback #3: Crosschain Asset Offering/trading remains a hypothesis at this stage

We do not agree with this feedback. It is our view that as the industry evolves and an ecosystem such as Stellar grows and matures, it will have no choice but to support crosschain tokenized assets offering and trading as users on all chains would expect this feature/capability to be available over time.

The product:

A solution designed for crosschain asset transfers, facilitating the exchange and management of digital assets between the Stellar and Polygon networks. It leverages the Soroban smart contracts and interoperability standards set by the Enterprise Ethereum Alliance to ensure seamless communication and transactions across different blockchain networks.

What problems it solves, how it solves them, and what audience it solves them for (explain the benefits):

Interoperability is a primary concern of financial institutions and regulators interested in DLT-based financial innovations. The Enterprise Ethereum Alliance (EEA) Distributed Ledger Technology Interoperability Specification is an open specification aiming to establish a secure and efficient framework for interoperability between different blockchain networks, focusing on enterprise applications. This specification addresses the need for various blockchain platforms to interact and transact seamlessly in regulated sectors like financial services.  It is designed to support enterprise blockchain networks using diverse underlying technologies (for example EVM and non-EVM networks), facilitating complex multi-chain ecosystem deployments involving assets, payments, and securities transactions. 

Enhancing the interoperability of the Stellar network with other blockchain ecosystems, such as Polygon in a way that is compliant with the EEA specification, broadens the scope, utility and relevance of Stellar-based assets and applications for enterprises, financial institutions and regulators looking for and prioritizing standard-compliant implementations.

Exploring EEA-compliant interoperability between Stellar and the Ethereum ecosystem can further enhance trust among various Stellar’ stakeholders including financial institutions, users, partners and regulators as well as demonstrating a commitment to address those stakeholders’ needs. It would also support collaboration between ecosystems.

Most importantly, how it works and how it uses Stellar and/or Soroban.

The solution will deliver a Stellar-Polygon Asset Bridge and a PoC for a Stellar Cross-Chain Atomic Swaps capabilities. It leverages Wanchain Message Bridge (WMB) framework and the EEA DLT Interoperability specification. Soroban is used for its advanced smart contract capabilities, providing the infrastructure for creating and executing contracts that manage and transfer digital assets securely.  To know more about how it works and how it uses Stellar and Soroban, please refer to the technical architecture document for further details.

Anaïs Ofranc - Founder - QualitaX

Anaïs Ofranc is the Founder of QualitaX, a company providing provide research and integration services for Distributed Ledger Technology (DLT) in the Finance industry.  Her work in the emerging tech space, started in 2020 with the Baseline Protocol and includes collaborations with startups and major firms like EY, Microsoft, and Consensys. Anaïs led the research on DLT interoperability available: https://qualitax.gitbook.io/interop/.

Anaïs brings over 15 years of experience in technology and FinTech having previously founded and led Consianimis Consulting for over nine years. Consianimis clients included Yahoo, the New Scientist, Informa, UBM, Ascential, dopay and others.

She is a member of the UK's DLT/1 - Blockchain and Distributed Ledger Technology Committee. Anaïs holds MSc in Computer Science and a MSc in International Strategic Management from Oxford Brookes University. Anaïs is a co-chair of the EEA Crosschain Interoperability WG and one of the three authors of the EEA DLT Interoperability Specification.

Dr Weijia Zhang - Head of Engineering - Wanchain

Dr Weijia Zhang is the Vice President Of Engineering at Wanchain Foundation. Wanchain is a decentralized blockchain interoperability solution that aims to drive blockchain adoption through interoperability. Wanchain bridges are decentralised, direct, non-custodial bridges that connect both EVM and non-EVM networks without requiring any centralised intermediaries. These bridges use a combination of Secure Multiparty Computation (sMPC) and Shamir’s Secret Sharing to secure crosschain assets.  With an extensive background in R&D and engineering, his expertise spans blockchain, cognitive sciences, mental modeling, Computational Fluid Dynamics (CFD), software modeling, computer technologies, and industrial standards. He has authored over thirty research and technical papers and holds more than twenty patents in computer and digital technology.  Weijia holds a BSc in Engineering Physics from Tsinghua University and a PhD in Physics from the University of Nebraska Lincoln.  Weijia is a co-chair of the EEA Crosschain Interoperability WG and one of the three authors of the EEA DLT Interoperability Specification.

Developers - Wanchain

Experienced developers from the Wanchain team based will deliver the work.

• Deliverable #1: Call a Soroban Smart Contract from an EVM blockchain (Polygon).

- Brief description: This deliverable is to establish a messaging bridge from an EVM chain (Polygon) to Soroban by leveraging the messaging protocol of EEA Interoperable Specification to initiate a function call from Polygon network to a smart contract on Soroban. The messaging will be signed by the messaging agent and the proof is verified by the onchain smart contract to ensure security.

- How to measure completion: The solution demonstrates that function calls from Polygon to Soroban are supported (i.e. successful integration testing showing correct signing, transmission, and handling of messages).

- Estimate date of completion: 2 weeks from project start date

- Budget:  $12,763.50 (67 hours)

• Deliverable #2: Call a smart contract from Soroban to another smart contract on an EVM chain (Polygon)

- Brief description: This deliverable is to establish a messaging bridge from Soroban to Polygon chain through the messaging protocol of EEA Interoperable Specification.  A rust library of smart contracts on the Soroban chain will be built to mimic the events, signatures, and proofs defined in the EEA Interoperability Spec. We have already done preliminary work on this.

- How to measure completion: The solution demonstrates that function calls from Soroban to Polygon are supported (i.e. successful integration testing showing correct signing, transmission, and handling of messages). We have already done preliminary work on this.

- Estimate date of completion: 4 weeks from project start date

- Budget:  $8,953.50 (47 hours)

• Deliverable #3: Stellar-Polygon Asset Bridge

This deliverable is to implement a Stellar-Polygon Asset bridge supporting use cases such as a seller who owns tokens on Stellar can offer token sales to prospective buyers on an EVM chain such as Polygon. An asset smart contract, broker smart contract, and messaging smart contract will be developed and linked. The messaging data format for this application will be defined and passed to the target chain through a messaging agent. On the target chain side, a broker smart contract will be developed to provide a Buy function for prospective buyers.

- How to measure completion: The solution successfully demonstrates that a buyer on Polygon can purchase an asset originating from Stellar.

- Estimate date of completion: 5 weeks from project start date

- Budget: $10,858.50 (57 hours)

• Deliverable #4: Stellar Cross-Chain Atomic Swaps

Leveraging the learnings from the previous deliverables, this deliverable is to develop a Stellar Cross-Chain Atomic Swaps proof of concept supporting advanced use cases such as Delivery versus Payment where a seller can transfer an asset through atomic crosschain transaction by using Hash Time Lock Contract (HTLC). 

- How to measure completion: The solution successfully demonstrates that the DvP use case is supported.

- Estimate date of completion: 6 weeks from project start date

- Budget: $7,429.50 (39 hours)

Budget was calculated based on blended hourly rate of USD$190.50.