Arya Pratap Singh

Posted on Sep 7

FestFund: Private Contributions & Public Recognition - A Zero-Knowledge Fundraising Solution

#devchallenge #midnightchallenge #web3 #webdev

Midnight Network Challenge: Protect That Data

This is a submission for the Midnight Network "Privacy First" Challenge - Protect That Data prompt.

Quick Links:

Tech Stack:

Note: Terms Donor and Contributor have been used interchangebly and mean the same 'THE VALUE ADDITION PARTY WHICH GENERATES A ZKP.

What I Built

FestFund solves fundraising's one of the hardest paradox: the choice between donor privacy and transparent recognition. Using Midnight Network's ZK infrastructure, I built a platform where donation amounts/transactions/wallet addresses/names are other important parameters remain completely private while maintaining verifiable public leaderboards and milestone tracking.

The Innovation Proposed: Cryptographically proving fundraising progress without exposing individual contribution amounts - making privacy and transparency work together, and making sure the figures (not shown) are valid (using commitments generated).

Demo

🌐 Live Frontend: https://festfund.vercel.app/

📋 Note: The live demo showcases the complete UI/UX but smart contract features run locally via Hardhat to keep the project cost-free. Full blockchain functionality available in local development setup. Use hardhat blockchain to create wallets. Hence the deployed service [vercel frontend and koyeb backend] is ought to NOT work due to contracts not being deployed on real blockchain. It just serves as a high level skeleton for now - you have to run it locally for full experience.

🎥 Demo Videos (Both videos are same, kindly ignore my Voice speed sometimes and errors midway were resolved in few minutes but the part is cut to save time):

📂 GitHub Repository: ARYPROGRAMMER/FestFund

How I Used what I like about Midnight's Technology

Performance: Midnight Network reduced ZK proof generation from 418ms to 1ms - a 418x improvement.

Core Integration:

Midnight Testnet-02 RPC: Live ZK operations via https://rpc.testnet-02.midnight.network
Official SDK: @midnight-ntwrk/zswap package for cryptographic primitives
Dual Architecture: Automatic fallback between Midnight Network and self-hosted mode

High Level Architecture Diagram

Snippet for Implementation:

// Real Midnight Network integration
const zkProof = new ZKProofIntegration();
await zkProof.initialize("midnight-network");

// Generate private commitment (1ms with Midnight vs 418ms self-hosted)
const commitment = await zkProof.generateDonationCommitment(
  amount,
  donorSecret,
  eventId,
  minimumAmount
);

Midnight's pre-optimized circuits and production infrastructure eliminated complex setup while providing enterprise-grade reliability and comprehensive documentation. Mine was using powersoftau (8) and it had the latency of 430ms (max) for same zkp. Midnight had 3 ms (max-rare) + is more secure as per my tests.

Screenshots of the Platform and Making / Debugging:

Data Protection as a Core Feature

Privacy forms FestFund's foundational architecture through hardest encryption algorithms, guarantees:

🔒 Zero-Knowledge Privacy:

Individual donation amounts cryptographically hidden using ZK commitments.
Platform administrators cannot access raw donation data.
Nullifier protection prevents double-spending without revealing amounts (Controversial, in this case its allowed once per wallet address).

🏆 Transparent Accountability:

Public leaderboards show donor rankings without exposing amounts (Donor given a choice for this parameter while contributing).
Milestone progress verifiable through cryptographic proofs.
Campaign organizers receive aggregate data while preserving individual privacy.

Real-World Impact:

Enables private donations for sensitive causes (political, medical, controversial).
Maintains donor recognition through transparent rankings.
Ensures regulatory compliance via mathematically provable privacy.

Set Up Instructions / Tutorial

Prerequisites:

Node.js 18+, MongoDB, MetaMask wallet / Hardhat

Quick Start:

# Clone repository
git clone https://github.com/ARYPROGRAMMER/FestFund.git
cd FestFund

# Hardhat (new terminal, root dir, precompiled in github)
npx hardhat node
npm run deploy 

# Backend setup
cd backend && npm install && npm start
# ✅ Backend: http://localhost:3001

# Frontend setup (new terminal)
cd ../frontend && npm install && npm run dev
# ✅ Frontend: http://localhost:3000

Environment Configuration [DEV]:

# Backend .env can be ignored , backend can take from root

root .env:

NODE_ENV=development
APP_URL=http://localhost:3000
USE_MOCK_MODE=true
PORT=3001
BACKEND_URL=http://localhost:3001
CORS_ORIGIN=http://localhost:3000,http://localhost:3001
NEXT_PUBLIC_BACKEND_URL=http://localhost:3001
NEXT_PUBLIC_APP_NAME=FestFund
NEXT_PUBLIC_APP_DESCRIPTION=Privacy-First Donation Platform
NEXT_PUBLIC_USE_MOCK_WALLET=true
NEXT_PUBLIC_ENABLE_ANALYTICS=false
NEXT_PUBLIC_ENABLE_NOTIFICATIONS=true
NEXT_PUBLIC_DEFAULT_THEME=light
MONGODB_URI=&appName=
JWT_SECRET=your-super-secret-jwt-key-change-for-production
BCRYPT_SALT_ROUNDS=12
GEMINI_API_KEY=
NEXT_PUBLIC_BLOCKCHAIN_RPC=http://localhost:8545
NEXT_PUBLIC_CHAIN_ID=31337
PRIVATE_KEY=7c60d2cd7f18a7891ae8b169f2fdf082d44206acf9c331e81113343537b81fd0
NEXT_PUBLIC_FUND_MANAGER_ADDRESS=0x9fE46736679d2D9a65F0992F2272dE9f3c7fa6e0
NEXT_PUBLIC_VERIFIER_ADDRESS=0xe7f1725E7734CE288F8367e1Bb143E90bb3F0512
NEXT_PUBLIC_MOCK_ERC20_ADDRESS=0x5FbDB2315678afecb367f032d93F642f64180aa3
ZK_MODE=midnight-network
NEXT_PUBLIC_ZK_MODE=midnight-network
ZK_CIRCUIT_PATH=./zk/circuits
ZK_PROVING_KEY_PATH=./zk/build/proving_key.zkey
ZK_VERIFICATION_KEY_PATH=./zk/build/verification_key.json
ZK_CIRCUIT_WASM_PATH=./zk/build/donation_commitment_v1.wasm
VERIFIER_CONTRACT_PATH=./contracts/Verifier.sol
MIDNIGHT_RPC_URL=https://rpc.testnet-02.midnight.network
MIDNIGHT_INDEXER_URL=https://indexer.testnet-02.midnight.network/api/v1/graphql
MIDNIGHT_INDEXER_WS_URL=wss://indexer.testnet-02.midnight.network/api/v1/graphql/ws
MIDNIGHT_NETWORK_ID=TestNet
MIDNIGHT_WALLET_SEED=your_64_character_hex_seed_here_or_mnemonic_phrase
NEXT_PUBLIC_MIDNIGHT_RPC_URL=https://rpc.testnet-02.midnight.network
NEXT_PUBLIC_MIDNIGHT_NETWORK_ID=TestNet
NEXT_PUBLIC_MIDNIGHT_EXPLORER_URL=https://polkadot.js.org/apps/?rpc=wss%3A%2F%2Frpc.testnet-02.midnight.network
ENABLE_LOGGING=true

# My Frontend .env.local
NEXT_PUBLIC_BACKEND_URL=http://localhost:3001
NEXT_PUBLIC_APP_NAME=FestFund
NEXT_PUBLIC_APP_DESCRIPTION=Privacy-First Donation Platform with Zero-Knowledge Proofs
NEXT_PUBLIC_CHAIN_ID=31337
NEXT_PUBLIC_ENABLE_ANALYTICS=false
NEXT_PUBLIC_ENABLE_NOTIFICATIONS=true
NEXT_PUBLIC_BLOCKCHAIN_RPC=http://localhost:8545
NEXT_PUBLIC_FUND_MANAGER_ADDRESS=0x9fE46736679d2D9a65F0992F2272dE9f3c7fa6e0
NEXT_PUBLIC_VERIFIER_ADDRESS=0xe7f1725E7734CE288F8367e1Bb143E90bb3F0512
NEXT_PUBLIC_MOCK_TOKEN_ADDRESS=0x5FbDB2315678afecb367f032d93F642f64180aa3
NODE_ENV=development

Testing ZK Integration:

Create campaign → Make private donation → Observe 1ms ZK proof generation
Check leaderboard → See rankings without amount exposure
Verify milestone achievements are cryptographically proven

Architecture: Next.js frontend, Express.js API, MongoDB persistence, Circom circuits with Midnight Network integration, Hardhat smart contracts.

Built with 💜 for the Midnight Network community - Arya Singh

More details / queries, email - arya.2023ug1104@iiitranchi.ac.in

Top comments (16)

Joselyn Lee • Sep 9

@aryprogrammer, I was trying to run your project demo locally, and a couple of things came across my mind.

At 13:13, your wallet link doesn't work.
It's not connecting to Midnight network, instead to ETH, check 13:37
MongoDB is based on web2.0 infrastructure (as per 19:33, so data is mutable)
Most of the things in the live demo doesn't work, and are hardcoded or either mocked.

It doesn't follow the given prompt (Protect That Data) guidelines, does it?

Arya Pratap Singh • Sep 9 • Edited

Thanks for the feedback,

It did connect to wallet link when I tried it again.
It didn't connect to midnight network and to ETH because I was testing it ut as well.
MongoDB was used to temporarily store the data so it could be contrasted later on.
It's a live demo and uncut testing, it used bit of mock things but yeah obviously it works in local. I have mentioned that as well in the Notes. Moreover I had read the guidelines multiple times and assure you it follows them exact to the point. I also uploaded the demo video for the same purpose. It justifies the problem statement as well which I'm trying to solve.

Thank you sincerely