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Mechon70x7
Mechon70x7

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ZK-ID: Privacy-First Identity Verification

#devchallenge #midnightchallenge #web3 #blockchain

Midnight Network Challenge: Protect That Data

This is my submission for the Midnight Network "Privacy First" Challenge

This tutorial shows how to set up, run, and verify the ZK-ID DApp for the "Protect That Data" challenge. It also demonstrates how the identity attestation works using mocked zero-knowledge proofs.

🔨 What I Built

ZK-ID is a decentralized identity verification DApp that allows users to prove who they are without revealing sensitive personal information.

By leveraging zero-knowledge proofs and privacy-first design, users can authenticate themselves securely while keeping their data safe from exposure.

🎥Demo

GitHub Repo: [https://github.com/Mechon70x7/zk-id.git]

🛠️ How I Used Midnight's Technology

This project integrates Midnight’s Compact language and SDK to:

Implement private smart contracts for identity validation.

Use confidential transactions to ensure sensitive data never leaves the user’s control.

Provide auditable yet private interactions, balancing compliance with security.

🔒 Data Protection as a Core Feature

Privacy isn’t an afterthought—it’s built into the architecture:

Zero-Knowledge Proofs allow verification without exposing raw data.

Selective Disclosure ensures users control exactly what they share.

On-chain privacy guarantees that no sensitive identity data is stored publicly.

1️⃣ Project Setup

Clone the Repository 

git clone <your-repo-url>
cd zk-id-frontend
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Install Dependencies 

npm install
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Start the Development Server 

npm run dev
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Deploy contracts using Midnight SDK (see /contracts folder).

Interact with the DApp via the frontend.

Open your browser at http://localhost:5173 to see the app.

2️⃣ User Interface Overview

Initial Input Form

  • User enters User ID (e.g., Alice)
  • User enters Birth Year (e.g., 2000)

Generate Proof button triggers verification.

3️⃣ Proof Generation and Verification

3.1 Enter User Information

  • User ID: Alice
  • Birth Year: 2000

3.2 Click Generate Proof

Console log shows the internal steps:

Submit clicked
User ID: Alice
Birth Year: 2000
Current Year: 2025
Proof result: { valid: true }
Submitting proof to contract... Alice true
Verified status: true
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3.3 Display Verification Status

Identity Verified (age ≥ 18)

  • Message displayed: ✅ Identity Verified

Identity Not Verified (age < 18)

  • Change birth year to 2010
  • Click Generate Proof
  • Message displayed: ❌ Identity Not Verified

4️⃣ Multi-User Support

The app supports multiple users independently:

  • User 1: Alice → 2000 → Verified ✅
  • User 2: Bob → 2010 → Not Verified ❌

Console shows separate proof results for each user.

5️⃣ Running Unit Tests

Run all tests to verify logic:

npm run test
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Tests include:

  • Single user verification
  • Multi-user verification
  • Age ≥ 18 / Age < 18 scenarios

👥 Team / Credits

Built by @mechon70x7

8️⃣ Notes for Reviewers

  • Privacy-Preserving Mechanism: Birth year input remains private; proof generation is mocked.
  • Zero-Knowledge Concept: generateProof() simulates ZK verification; no real-world value is used.
  • Multiple Users: Each user is verified independently, demonstrating decentralized handling in UI.

!!THANKS!!

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