ContentPrivacyNFT

Description

This project aims to address the issue of indiscriminate access to data contained within decentralized platforms that regulate the ownership of digital assets through Non-Fungible Tokens (NFTs). While NFTs have been widely used for digital asset ownership, the public accessibility of the associated data poses a challenge for asset owners in certain scenarios.

The goal of this project is to design and implement a framework for publishing NFTs that maintains compliance with standards while integrating privacy-enhancing tools such as zero-knowledge proofs (ZKP). By leveraging ZKP, the framework aims to enable confidentiality of the NFT content without compromising its usability. However, the inefficiency of such tools presents a significant challenge, requiring extensive experimental work to identify practical solutions in real-world scenarios.

Prerequisites

• Circom (v2.0.0)
• Snarkjs (v0.6.10)
• RapidSnark (v0.0.0)
• Python (v3.10)
  • Numpy (v1.24.0) [Python package]
  • Tensorflow (v2.12.0) [Python package]
  • OpenCV (v4.7.0) [Python package]

Recommandations

Since the snarks usually take a long time to generate, it is recommended to unlock nodejs memory limit by running the following command:

export NODE_OPTIONS="--max-old-space-size=8192" # 8 GB as example

Morover follow the recommandations provided in the following link to improve the performance of the snarks generation.

Installation

After cloning the repository, it is necessary to modify the following file in order to set the correct paths:

• Modifiy the path of the rapidsnark library in scripts/proving_system/prover.sh.
• Set the powersoftau file in image_proof.py

After that ensure that the following directories exist:

├── circuits
│   └── base
│       └── poseidon2
├── input
├── output
├── scripts
│   ├── image_ops
│   └── proving_system

Usage

To generate an image proof, use the following command:

./image_proof.py --image <image_path> --operation <operation_info> --frame-pixel <frame_pixel> [--check-pixel <check_pixel>] [--save-tiles <save_tiles_path>] [--save-image <save_image_path>] [--generate-csv] [--generate-contract]

• <image_path>: Path to the image file for which you want to generate the proof. Only PNG images are supported.
• <operation_info>: Image operation to perform. Currently, only "resize" operation is implemented. Specify the dimensions of the operation in the format <height>x<width>. For example, "resize_22x22" will resize the image to 22x22 pixels.
• <frame_pixel>: Number of pixels to divide in the greatest dimension of the frame.
• <check_pixel> : Maximum number of pixels to divide in order to respect a threshold. If specified, the script will calculate the maximum number of pixels per frame based on the threshold and print the result.
• <save_tiles_path> (optional): Path to save the frames as individual images.
• <save_image_path> (optional): Path to save the low-resolution image.
• --generate-csv (optional): Generate a CSV file with time and memory usage for each frame.
• --generate-contract (optional): Generate a contract in Solidity for verifying the proof on Ethereum.

Example Usage:

To generate a proof for an image tux.png, with a frame size of 32 pixels, and save the frames and low-resolution image that is in this case the resize of the original image to 22x22 pixels, use the following command:

./image_proof.py --image ./input/tux.png --operation resize_22x22 --frame-pixel 32 --save-tiles ./output/tiles --save-image ./output/resize_tux.png --generate-csv --generate-contract

License

This project is licensed under the MIT License - see the LICENSE file for details.