Don't take our word for it. Open-source, client-side verification of Signos-sealed photos and videos.
Verify the authenticity of Signos-sealed media. Everything runs in your browser — your file never leaves your device. No backend required, no account needed, no API keys.
Live at verify.signos.app
| Check | What it proves |
|---|---|
| Content Hash | The file hasn't been modified — BLAKE3 fingerprints every byte |
| Timestamp Record | When it was created — hash registered on the Algorand blockchain |
| Human Presence | A real person held the camera — biometric motion data cross-verified on-chain |
| Signos Wallet | The registration wallet belongs to a verified Signos device |
- Hash the file — BLAKE3 generates a unique 256-bit fingerprint of the exact bytes (running in WASM, ~500 MB/s in your browser)
- Extract metadata — Read the embedded verification instructions from the file's XMP (images) or QuickTime metadata (videos)
- Search the blockchain — Look up the hash on the Algorand public indexer (no Signos servers involved)
- Cross-verify — Compare the biometric motion proof and wallet registration against the on-chain record
- Display the verdict — Pass, fail, or "unable to verify"
No file upload. No analytics. No tracking. The verification is purely cryptographic — every byte of the result can be reproduced independently with the same inputs.
- Open verify.signos.app
- Drag and drop a Signos-sealed file (JPEG, HEIC, PNG, MOV, MP4) onto the page
- Watch the four checks run live
Want to see one without taking a photo? Pull any sealed file from the wild — every Signos user is publishing them.
git clone https://github.com/Signos-app/verify.git
cd verify
npm install
npm run devnpm run buildOutput goes to dist/. Deploys cleanly to any static host (Cloudflare Pages, Vercel, Netlify, GitHub Pages, an S3 bucket, your own server).
- Vite + TypeScript — fast builds, minimal runtime
- BLAKE3 via
blake3npm (WASM) — cryptographic hashing in the browser - ExifReader — XMP metadata extraction from images
- Algorand Indexer API — public, no API key, no account
- Custom QuickTime atom parser for video metadata extraction
Total source: ~3,000 lines of TypeScript. Zero dependencies on the Signos backend.
Signos files embed their own verification instructions. The architecture is patent-pending. The verification is open.
If Signos disappears tomorrow, anyone with this code (or any Algorand indexer endpoint) can still verify every file ever sealed. The sealed-file format will be published as an open spec at Signos-app/spec so third parties can build their own verifiers.
This is the point: trust the math, not the company.
C2PA is a consortium-controlled standard for content authenticity, championed by Adobe, Microsoft, BBC, and others. It signs files with PKI certificates issued by member organizations.
Signos anchors content hashes on a public blockchain instead of using PKI. Files are verifiable independently of any company, certificate authority, or consortium. There's no central root of trust to revoke or compromise. C2PA and Signos can coexist on the same file — they answer different questions.
The Signos sealed-file format is an open specification: Signos-app/spec (coming soon).
See CONTRIBUTING.md. Issues and PRs are welcome. The code in this repo is synced from a private monorepo, so non-trivial PRs may be applied upstream and re-synced rather than merged directly.
For responsible disclosure of security issues, see SECURITY.md. Please do not open public issues for vulnerabilities.
MIT — © 2026 Signos LLC
Get the iOS app: signos.app · Verify any sealed file: verify.signos.app