zkTruth — Proof of Capture

Fight misinformation with cryptographic proof of reality.

zkTruth is a decentralized camera application that cryptographically proves media authenticity using zero-knowledge proofs and blockchain timestamping on World Chain.

In a world where AI-generated deepfakes are indistinguishable from reality, zkTruth establishes trust at the point of capture — not after the fact.

---

The Problem

• 4.7B AI-generated images created in 2025 alone
• 67% of people can't distinguish real from AI content
• 96% of deepfakes are created without consent

No existing solution simultaneously verifies that content was captured by a real device, at a specific time and place, by a verified human, and has not been tampered with since capture.

---

How It Works

📸 CAPTURE  →  🔐 VERIFY  →  ⛓ MINT & SHARE

1. Capture

Take a photo or video. GPS coordinates, UTC timestamp, and device metadata are embedded in real-time.

2. Verify

Authenticate with World ID using zero-knowledge proofs. Prove you're human without revealing your identity.

3. Mint & Share

SHA-256 content hash is minted as an ERC-721 NFT on World Chain (Chain ID: 480). Share your verified proof on any platform.

---

Key Features

Feature	Description
Zero-Knowledge Proof	World ID verifies you're human without revealing identity
Content Hashing	SHA-256 tamper-proof fingerprint generated at capture time
On-Chain Record	Immutable timestamp and proof on World Chain
Real-Time Metadata	GPS, time, device info overlaid on camera view
Social Sharing	Export verified proof to X, Instagram, Farcaster
Photo & Video	Supports both photo capture and video recording
Mobile-First PWA	Optimized for iPhone/Android with native camera access

---

Technology Stack

Layer	Technology	Purpose
Frontend	Next.js 16 + React 19	PWA camera application
Identity	World ID (ZKP)	Human verification
Integrity	SHA-256 + C2PA (Phase 2)	Tamper detection
Blockchain	World Chain (ID: 480)	Immutable proof storage
Wallet	Privy (embedded wallets)	Non-custodial wallet
Storage	Arweave / Irys (Phase 2)	Permanent media storage

---

Getting Started

Prerequisites

• Node.js 18+
• npm or yarn

Installation

git clone https://github.com/manmos104/zktruth.git
cd zktruth
npm install --legacy-peer-deps

Development

# HTTP (desktop browser testing)
npm run dev

# HTTPS (required for mobile camera access)
npx next dev --experimental-https -p 3000

Open https://localhost:3000 in your browser.

Mobile Testing

1. Run HTTPS dev server: npx next dev --experimental-https -p 3000
2. Find your local IP: ipconfig getifaddr en0
3. Open https://<your-ip>:3000 on your phone's browser
4. Accept the self-signed certificate warning

---

Architecture

┌─────────────────────────────────────────────┐
│                 zkTruth App                  │
│         (Next.js PWA / React 19)            │
├──────────┬──────────┬───────────────────────┤
│  Camera  │ Metadata │    UI / Sharing       │
│  Module  │ Overlay  │    Module             │
├──────────┴──────────┴───────────────────────┤
│            Proof of Capture Engine           │
│  ┌────────┐ ┌─────────┐ ┌────────────────┐  │
│  │SHA-256 │ │World ID │ │  GPS + Time    │  │
│  │Hashing │ │  (ZKP)  │ │  Capture       │  │
│  └────┬───┘ └────┬────┘ └───────┬────────┘  │
│       └──────────┼──────────────┘            │
│                  ▼                            │
│         Proof Structure (JSON)               │
├──────────────────────────────────────────────┤
│          World Chain (ID: 480)               │
│     ERC-721 NFT + Immutable Timestamp        │
└──────────────────────────────────────────────┘

---

Roadmap

Phase 1: MVP ✅ Complete

• Mobile-first PWA camera with real-time metadata overlay
• SHA-256 content hashing at capture time
• World ID integration (zero-knowledge human verification)
• Social sharing with embedded proof data
• Photo and video capture support
• Splash screen with brand animation

Phase 2: On-Chain Infrastructure 🔄 In Progress

• ERC-721 smart contract deployment on World Chain
• Real NFT minting with on-chain attestation
• C2PA integration for media authenticity standard
• Arweave / Irys permanent storage
• Gasless minting for World ID verified users

Phase 3: Ecosystem & Scale 📋 Planned

• Public verification portal
• API for third-party integration
• Media organization partnerships
• Multi-chain expansion (Ethereum, Optimism, Base)
• Proof of Capture SDK for developers

---

Use Cases

• 🏛 Citizen Journalism — Verify war zone footage and eyewitness reports
• ⚖️ Legal Evidence — Tamper-proof photographic evidence for courts
• 🌱 Environmental Monitoring — Authenticated deforestation/pollution records
• 🎨 Content Authenticity — Creators prove original authorship vs AI copies
• 🗳 Election Monitoring — Verified records of polling stations

---

Security Model

Threat	Mitigation
Content manipulation	SHA-256 hash detects any modification
Identity spoofing	World ID biometric uniqueness (1 person = 1 ID)
Timestamp manipulation	Blockchain consensus on World Chain
Metadata forgery	On-device capture binding

Honest Limitations

zkTruth proves when, where, and by whom media was captured, and that it hasn't been modified. It does not verify the semantic meaning of content (e.g., photographing a screen showing fake content).

---

Project Links

• GitHub: github.com/manmos104/zktruth
• World Developer Portal: developer.worldcoin.org
• World Chain Explorer: worldchain-mainnet.explorer.alchemy.com

---

License

MIT License — see LICENSE for details.

---