# Implementing Noir Verifier within Cairo

## Introduction

The objective of this proposal is to methodically translate the functionality of the Noir verifier, primarily written in Solidity, to be compatible with Cairo. While the core of the Noir verifier remains consistent, dynamic segments such as the verification keys need specialized attention. This transformation will pave the way for Cairo to efficiently and effectively verify Noir proofs.

## Rationale

As zero-knowledge proofs continue to grow in significance, the synergy between Noir and Cairo becomes crucial. Noir, with its unique DSL for SNARKs, generates verifiers in Solidity. By transposing this verifier to Cairo, we intend to enhance its versatility and open up new avenues for cross-platform integration.

## The Strategic Approach

### 1. Detailed Analysis of the Noir Verifier

- Conduct a comprehensive examination of the [Noir verifier in Solidity](https://github.com/visoftsolutions/noir-ink/blob/main/contract/noir_ink/plonk_vk.sol).
- Identify segments that remain static and those that need dynamic implementations, especially the section that [changes between different verifiers](https://github.com/visoftsolutions/noir-ink/blob/main/contract/noir_ink/plonk_vk.sol#L12-L70).

### 2. EC Pairing Challenge: A Considered Solution

- Recognize the complexities associated with the EC pairing component, as shown [here](https://github.com/visoftsolutions/noir-ink/blob/main/contract/noir_ink/plonk_vk.sol#L2582). This precompiled contract introduces challenges in its direct implementation within Cairo.

- Leverage insights from resources that elucidate [Solidity's precompiles](https://www.rareskills.io/post/solidity-precompiles) to understand its intricacies.

- Explore potential solutions provided by [garaga](https://github.com/keep-starknet-strange/garaga) to address the EC pairing challenge, as it presents tools and functions that might simplify the process.

### 3. Implementation Roadmap

1. **Adaptation of Static Components**:
- Migrate and adapt the static components of the Noir verifier from Solidity to Cairo. This would use the majority of the verifier as a template for implementation.

2. **Translation of Dynamic Components**:
- Special attention to be given to the dynamic verification keys section to ensure its accurate implementation in Cairo.

3. **EC Pairing Solution**:
- Develop a tailored EC pairing solution in Cairo, leveraging any applicable functionalities from garaga.
- Validate the integrity and performance of this solution, ensuring its compatibility and efficiency.

4. **Testing & Validation**:
- Post-implementation, conduct rigorous testing to validate the complete functionality of the Noir verifier within Cairo.
- Emphasize testing the EC pairing segment to ensure its reliable operation.

## Conclusion

Migrating the Noir verifier's capabilities into Cairo, while challenging, promises significant strides in enhancing the versatility and reach of zero-knowledge proofs. By addressing the intricacies, especially around EC pairing, and leveraging tools like garaga, we aim to establish a robust Noir verifier within the Cairo ecosystem.