# Background
During the past 1.5 years, We ([Manta.Network](https://www.manta.network/)) developed the on-chain privacy solution for DOT/SAMA eco-systems using zkSNARKs, here are some highlights:

**Dolphin Testnet V1(unincentivized)**

- 60,000 + transactions
- 6,000+ distinct addresses
- send more private transaction powered by zkSNARK in 3 months than Tornado.cash in 1 year

> "The Dolphin Testnet] is really good... The experience is really pleasing, congrats to
  the team.”
>                                                              (Thibaut Sarda, Core Developer, Polkadot.js)

**Dolphin Testnet V2**

- 1/10 ZCash's (Sapling) constraints count in zero-knowledge-proof circuit
- Improved prover performance from 30 sec to 2 sec

As the first project in the substrate space (and very few in the entire Web 3 space) working on zero-knowledge-proof based developed, we experienced a lot of difficulties in terms of ZKP tooling. As a result, we developed a lot of internal tooling that could benefit peer substrate teams deploying zero-knowledge-proof techniques securely and quickly into their project. 

# Potential Applications
- DID projects like KILT can leverage OpenZL to make their KYC/AML process more decentralized
- Cross-chain Bridges can leverage OpenZL to make the bridges high-performance and trust-less
- DAO tooling project can leverage OpenZL to build MACI for governance
- Project like Astar can leverage OpenZL to build ZKRollups 

and many more

# OpenZL Design
![](https://user-images.githubusercontent.com/720571/167014503-10117012-c898-4d54-802a-966eb02dab98.svg)

OpenZL is an open-source library that helps practioners (especially in Web3 space) to develop and deploy secure, high performance zero-knowledge proof code in production. It tries to bridge the gap between low level cryptographic primitives and devlopers' need to build scalable protocols using zero-knowlege proof cryptography securely and quickly. More specifically, many developers today want to leverage zero-knowledge proof systems to build powerful protocols like ZCash/Manta/ZKSync. However, they are facing two less than ideal choices; first, building a protocol using high-level languages like [Circom](https://docs.circom.io/) or [Cairo](https://www.cairo-lang.org/) loses many performance optimization opportunities, and second, building the protocol directly using libraries like [arkworks/groth16](https://github.com/arkworks-rs/groth16), [zk-garage/plonk](https://github.com/zk-garage/plonk), or [microsoft/nova](https://github.com/microsoft/Nova) requires expertise in cryptography and can be very error-prone. Also, zero-knowledge proof systems are a moving target. There have been many new, and "better", proof systems coming out every 2-3 years ([BCTV](https://eprint.iacr.org/2013/879.pdf) -> [Groth16](https://eprint.iacr.org/2016/260.pdf) -> [Plonk](https://eprint.iacr.org/2019/953) -> [Nova](https://eprint.iacr.org/2021/370)). OpenZL tries to solve this problem by building flexible, proof-system agnostic, and extensible libraries for Web3 practitioners.

OpenZL consists of 3 parts:

- Gadget libraries: a library of gadgets that developers can use as building blocks for their protocols. The initial range of the gadgets includes accumulators (merkle tree with zero-knowledge membership proof), zk-friendly hash functions (poseidon hash), and commitment schemes. The gadget libraries are programmed in eclair.
- Embedded Circuit Language And Intermediate Representation (eclair): An embedded DSL in Rust that describes circuit logic. eclair leverages Rust's expressive type system to rule out certain classes of errors during the circuit construction.
- Adaptors to Proof Systems: Adaptors that convert circuit logic in eclair to the constraint systems used in different proof systems. The initial supported proof systems are arkworks/groth16, zk-garage/plonk, and microsoft/nova.

# Technical Details and Budget:
Please find the technical details and budget in the following page:
[https://github.com/OpenZkLib/openzl/blob/main/proposal.md](https://github.com/OpenZkLib/openzl/blob/main/proposal.md)

Would love to get constructive feedbacks.

- Manta.Network developed a privacy solution for DOT/SAMA ecosystems using zkSNARKs.
- They conducted tests on the Dolphin Testnet V1 and V2, with a high number of transactions and improved performance.
- OpenZL is an open-source library that helps developers build secure and high-performance zero-knowledge proof code.
- OpenZL can be used in various applications like DID projects, cross-chain bridges, DAO tooling, and ZKRollups.
- OpenZL consists of gadget libraries, an embedded circuit language, and adaptors to different proof systems.

#1050 OpenZL: Common Good Zero-Knowledge-Proof Library for Substrate Builders

No Active Proposals