BlockFact vs HonMono.cam

BlockFact introduces .facti — a new image file format that proves a photo is authentic, unedited, and captured at a verified time and place. Every photo you take with BlockFact is cryptographically sealed at the moment of capture. The result is a .facti file—an image with built-in proof of origin that anyone can verify, without trusting the photographer, the platform, or us. HOW IT WORKS 1. Take a photo with BlockFact 2. Your device generates a zero-knowledge proof and Poseidon hash—entirely on-device, no upload required. 3. The proof is registered on the StarkNet blockchain. 4. A .facti file is built locally on your phone—containing the image, an invisible watermark, and the on-chain registration. The photo never leaves your device. Only a small cryptographic proof is sent to the blockchain. WHAT MAKES .FACTI DIFFERENT Unlike JPEG or PNG, a .facti file carries its own proof of authenticity: • When was it taken? Verified by on-chain timestamp. • Where was it taken? GPS coordinates sealed in the cryptographic hash • Who took it? Linked to the creator's blockchain wallet • Has it been edited? The invisible watermark and hash detect any tampering. Anyone can verify a .facti file at blockfact.io/verify—just drag and drop. WHO IS THIS FOR? • Journalists documenting events where authenticity matters • Photographers proving original work and protecting against AI-generated fakes • Legal and insurance professionals who need verifiable visual evidence • Content creators establishing provenance before publishing • Anyone who needs to prove a photo is real FOR DEVELOPERS BlockFact is also available as a React Native SDK (@blockfact/react-native-facti-pro) for developers building apps that need verified image capture. The BlockFact app is the reference implementation—try it to understand the .facti format, then integrate the SDK into your own product. PRIVACY BY DESIGN • Photos never leave your device—only a cryptographic hash is registered on-chain. • No accounts required beyond sign-in—no personal data collected • Zero-knowledge proofs mean the blockchain verifies your proof without seeing your photo. • Open verification—anyone can check a .facti file independently BUILT ON • StarkNet blockchain (Ethereum L2) • Groth16 zero-knowledge proofs via Arkworks • Poseidon hashing (quantum-resistant) • IANA-registered MIME type: image/vnd.blockfact.facti

In a world full of AI-generated images, HonMono makes your photos provably real. HonMono is a free iOS camera app that proves your photos and videos are authentic — at the moment you take them. Every capture is automatically stamped with a visible QR-code watermark and a cryptographic content credential, giving anyone instant, effortless proof that what they're seeing is genuine. How it works: Open HonMono and capture a photo or video just like you would with your normal camera. In the background, HonMono generates a C2PA-compliant content credential — a cryptographic fingerprint of the image content, timestamp, and device. At the same time, it embeds a visible QR code directly into the pixels of your photo. Share it anywhere — iMessage, WhatsApp, email, social media, or print. The QR code travels with the image, because it is part of the image. Anyone who receives your photo simply scans the QR code with their phone camera. No app download required. No technical knowledge needed. No account required. The verification page instantly confirms the image is authentic and unedited. Why HonMono? The C2PA standard is a powerful cryptographic protocol — but it has a last-mile problem. Social media platforms strip metadata. Messaging apps re-compress files. Screenshots destroy digital signatures. By the time a photo reaches the person who needs to trust it, the invisible proof is often already gone. HonMono solves this with two layers of verification: — C2PA cryptographic hash verification — the gold standard, when the original file is intact — Visible QR watermark — a fallback that survives compression, re-encoding, and screenshots, because it lives in the pixels, not the metadata Who is HonMono for? — Marketplace sellers on eBay, Craigslist, or Facebook Marketplace who want buyers to trust their product photos — Citizen journalists and activists documenting events that need to be believed — Field workers and professionals who need timestamped, verifiable photo records — Anyone who wants to send a photo and have the recipient know, without a doubt, that it's real Free. No account required to capture or verify. HonMono is free to use. Verification requires no account and no app — just a phone camera and a QR scan. Requires iOS 18 or later.