Please describe your proposed solution

To enhance transparency and security and reduce costs in the development of blockchain bridges on Cardano, we propose a bridge construction that uses Mithril signatures.

• To mint wrapped assets, the bridge smart contract on the destination will verify a Mithril certificate of deposit coming from the origin.
• To withdraw funds on the origin, a Mithril certificate of burning must be produced at the destination.

To keep the scope of this proposal realistic, we will only implement the bridging contract for Cardano, thus enabling transfers between isomorphic Cardano-like blockchains.

At the very least, the solution consists of the following components:

• A modified (forked) version of a Mithril signer capable of producing the required certificates.
• Arithmetic circuit for Mithril certificate verification.
• Bridge smart contract (written in zkFold Symbolic).
• Off-chain code to construct bridging transactions.

Besides the obvious utility for blockchain users, the ZK bridge can help monetize running Mithril signers, enabling other Mithril use cases.

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By leveraging open source collaboration, this solution will boost the security and functionality of the Cardano blockchain bridges. It will also foster the ecosystem of developers committed to advancing blockchain technology.

Please define the positive impact your project will have on the wider Cardano community

ZK bridges enable the secure transfer of assets between smart contract blockchains.

By completing this project, we will enable the simple creation of isomorphic Cardano-like sidechains that will have a positive impact on Cardano's scalability.

Mithril signature verification circuits are of independent value. They enable other use cases besides bridges, such as efficient on-chain voting.

Finally, this proposal is open-source. The outputs will be available for use by the whole Cardano developer community.

What is your capability to deliver your project with high levels of trust and accountability? How do you intend to validate if your approach is feasible?

ZKFold is the company that works on L1 and L2 scaling for Cardano using zero-knowledge proofs. It aims to release the first version of zkFold Symbolic (the zero-knowledge smart contract language) in Q3 2024. The zkFold team consists of expert Haskell, Rust, and ZKP developers. The founder of zkFold, Vladimir Sinyakov, previously completed a Project Catalyst Fund 6 grant leading the ENCOINS team. ENCOINS is a DApp on Cardano that has been recently launched on the mainnet. Also, zkFold is consistently delivering Fund 11 proposals' milestones.

Anastasia Labs is a research and development firm specializing in DApp development on Cardano. The team has made significant open-source contributions to the Cardano ecosystem; and has identified and resolved a large number of vulnerabilities in open-source code and smart contracts throughout the ecosystem. The team has a vast wealth of experience in the domain of smart contract security, advanced design patterns and production DApp development. Recently, the team has concentrated their efforts on the design and implementation of effective zero-knowledge proof applications within the Cardano ecosystem. The CEO and co-founder of Anastasia Labs, Philip DiSarro, has completed a number of Catalyst grants including Discovery (SundaeSwap Liquidity Bootstrap Mechanism) which recently launched on mainnet with overwhelmingly positive reception.

What are the key milestones you need to achieve in order to complete your project successfully?

Milestone 1: Create documentation

Milestone 2: Generate zero knowledge circuits for Mithril signature verification

Milestone 3: Build a bridge smart contract prototype (in zkFold Symbolic)

Milestone 4: Create a modified version of Mithril signer

Milestone 5: Create the signature aggregation backend component

Final Milestone: Complete bridge smart contract

Who is in the project team and what are their roles?

The zkFold team consists of expert Haskell, Rust, and ZKP developers. ZKFold's team members participated in the development of several successful projects on different blockchains, including Cardano, Polkadot, and Near. The zkFold team won the EMURGO BUILD Hackathon on the zero-knowledge track and took 3rd place in the Battle of the Builders at the Cardano Summit 2023 in Dubai. Also, zkFold's Fund 11 proposals have been accepted by the community.

zkFold

Vladimir Sinyakov

Founder and CTO,

<https://www.linkedin.com/in/vladimir-sinyakov/>

Founder and protocol architect of ENCOINS. Ph.D. in Computational Mathematics. Prior experience includes five years of postdoc in applied mathematics (Control Theory), publishing in top journals in the field. Previously completed a Project Catalyst Fund 6 grant leading the ENCOINS team. ENCOINS is a DApp on Cardano that has been recently launched on the mainnet.

Stanislav Marycev

Co-founder, Business Development.

<https://www.linkedin.com/in/stanislav-marycev/>

Bachelor degree in Business Management. Cardano Blockchain Certified Associate (CBCA). PMP and agile professional with 12+ years of experience in worldwide IT and blockchain projects. Stanislav has experience in leading multicultural international teams (30+ countries) and working closely with top level stakeholders in finance.

Ilya Eriklintsev

ZKP researcher,

<https://www.linkedin.com/in/ilya-eriklintsev-3a296852/>

Techlead at vSelf, an SSI solution on NEAR blockchain. More than six years of experience in the blockchain industry. Former researcher in Computational Fluid Dynamics.

Eitan Chatav

Developer

PhD in mathematics, expert in advanced mathematics and physics; probability and statistics, algebra, real and complex analysis. 5+ years of experience with blockchain, NFT, Haskell

Vladimir Morozov

Developer

B.Sc. in Applied Mathematics and Computer Science, PhD in Computational Biology. 6+ years of experience with Haskell and Python

Anastasia Labs

Philip DiSarro

Co-founder and CEO,

MS in Compiler Engineering. Expert in smart contract development and security. Completed numerous Project Catalyst Grants and brought multiple applications to the Cardano mainnet.

Jonathan Rodriguez

Co-founder and CTO,

B.Sc. in Robotics and Computer Science, along with a DevOps Architect certificate from the University of Toronto. With over 6 years of experience in blockchain technology, serving as a smart contract architect and conducting audits for high TVL projects within the Cardano ecosystem. Additionally, offering Web3 consulting services at Emurgo.

Please provide a cost breakdown of the proposed work and resources

Documentation and project management: 66,000 ADA

1 technical writer @ $3,000 per month for 5 months = $15,000 (~32,000 ADA)

1 software developer @ $3,000 per month for 2 months = $6,000 (~13,000 ADA)

1 project manager @ $2,000 per month for 5 months = $10,000 (~21,000 ADA)

Generate zero knowledge circuits for Mithril signature verification: 160,000 ADA

3 software developers @ $3,000 per month for 6 months = $54,000 (~115,000 ADA)

1 software developer @ $3,000 per month for 5 months = $15,000 (~32,000 ADA)

1 ZKP researcher @ $3,000 per month for 2 months = $6,000 (~13,000 ADA)

Build a bridge smart contract prototype (in zkFold Symbolic): 172,000 ADA

3 software developers @ $3,000 per month for 6 months = $54,000 (~115,000 ADA)

3 software developers @ $3,000 per month for 3 months = $27,000 (~57,000 ADA)

Create a modified version of Mithril signer: 45,000 ADA

1 software developer @ $3,000 per month for 4 months = $12,000 (~26,000 ADA)

1 ZKP researcher @ $3,000 per month for 3 months = $9,000 (~19,000 ADA)

Create the signature aggregation backend component: 38,000 ADA

1 software developer @ $3,000 per month for 4 months = $12,000 (~25,000 ADA)

1 ZKP researcher @ $3,000 per month for 2 months = $6,000 (~13,000 ADA)

Complete bridge smart contract: 19,000 ADA

1 software developer @ $3,000 per month for 3 months = $9,000 (~19,000 ADA)

Total: $235,000 = ~ 500,000 ADA

No dependencies.

How does the cost of the project represent value for money for the Cardano ecosystem?

The project requires a deep understanding of Cardano smart contracts and blockchain backend infrastructure, as well as expertise in zero-knowledge cryptographic protocols. As we pay competitive salaries to our developers and researchers, we've arrived at the budget breakdown above.

Interoperability is crucial to the success of our ecosystem. Even more so now with partner chains on the horizon. The most critical component of secure blockchain interoperability is a bridge. The construction of a secure bridge is a very difficult undertaking and perhaps one of the hardest problems in the space at large. However, by taking advantage of the years of research and work that went into the Mithril project, we are able to produce this bridge at a fraction of the cost of similar systems.