Hey Product Hunt! 👋 I built BlockFact because AI-generated images are now indistinguishable from real photos. We need a way to prove what's authentic. The Problem: Deepfakes and AI images are everywhere. Newsrooms can't verify photos from stringers. Insurance companies are seeing AI-generated damage claims. Legal Teams are dealing with deepfake evidence in court. There's no reliable way to verify whether a real camera actually took the photo. How BlockFact Works: 1. 📸 On-device capture — camera-only, blocks gallery uploads 2. 🔐 Zero-knowledge proof — Groth16 proof generated natively on your phone in <1 second (Rust/Arkworks) 3. 🖼️ Invisible watermark — Poseidon hash embedded in pixels, survives screenshots, cropping, and re-compression 4. ⛓️ On-chain verification — trustless Groth16 proof verified via Garaga on StarkNet — anyone can audit 5. 🔍 Perceptual verification — drop any image at blockfact.io/verify to check if it matches a registration, even degraded copies 6. 📱 Media never leaves your device — only the cryptographic hash and proof are sent to the blockchain Why It's Different: - ✅ Images never leave the device — privacy by architecture, not policy - ✅ Zero-knowledge proofs — verify capture conditions without revealing sensitive metadata - ✅ On-chain verification — no certificate authority to trust, verify on StarkNet directly - ✅ Survives distribution — watermark persists through screenshots, messaging apps, social media - ✅ IANA-registered media types—image/vnd.blockfact.facti, audio/vnd.blockfact.facta, video/vnd.blockfact.factv - ✅ ~7 seconds end-to-end — capture to blockchain registration - ✅ Free for everyone — 5,000 registrations per user, no paywall Current Status: - 📦 Pro SDK v5.0.0 on npm (@blockfact/react-native-facti-pro) - 📱 iOS & Android apps live on both stores - ⛓️ Live on StarkNet with on-chain Garaga Groth16 verification - 🌍 647 registrations across 12 countries - 📋 3 IANA-registered media types - 📖 Full docs at docs.blockfact.io - 🔬 Patent pending on AI agent trust verification (US 63/839,767) Try it: - 🔍 Verify an image → blockfact.io/verify - 📄 View a .facti file → blockfact.io/demo - 👨‍💻 Get the SDK → blockfact.io/developers Built solo from Jamaica 🇯🇲 — the entire stack: mobile apps, Rust native modules, ZKP circuits, Cairo smart contracts, and AWS backend. Would love your feedback! What use cases do you see for verified media? Key changes from the old version: - SDK version 2.5.1 → 5.0.0 - 15-25 seconds → ~7 seconds - Added on-device processing, ZKP, watermarking, perceptual verification - Added traction numbers (647 registrations, 12 countries) - Added patent reference - Corrected IANA media types (was wrong format) - Added the verify and demo links - "Built solo from Jamaica"

BlockFact

Tamper-proof photos in 5 seconds—from capture to blockchain

Tamper-proof photos in 5 seconds—from capture to blockchain