Available now on Android and iOS

Capture with confidence
Prove authenticity

Witness signs every photo and video at the moment of capture, embedding cryptographic proof directly into the file. No cloud uploads needed.

No trackers • No ads • Privacy First

Get your unique WitnessID
Your WitnessID links your captures to you and lets you register new devices.

Register for a WitnessID

Actual Witness App Interface

How it works

Three steps to verifiable truth.

01. Capture

Use Witness App

Take photos and videos directly in the app. Each capture is tied to your unique Witness ID and device signature.

02. Embed

Sign & Seal

The app creates a JSON manifest with cryptographic hashes and embeds it inside the MP4 or JPEG file.

03. Verify

Validate Anywhere

Anyone can check authenticity using the Web Validator. If the file is tampered with, verification fails.

See it in action

Android and iOS demos: capture → signing → verification

  • Signed at capture, not after
  • Portable JSON manifest inside the file
  • Gallery allows playback and shows content validation results

Android demo

iOS demo

Built for a world of AI media

Security, portability, and human presence are the core design constraints.

Secure foundation

On-device signing plus server-issued Delegated Signing Certificates (DSCs). If the file changes, the signatures don’t match — and verification fails.

Portable proof

Witness uses standard MP4 and JPEG files. The manifest is embedded in the file itself, so proof stays attached when you share or move content.

Human in the loop

Every capture links a real human Witness ID with a real device. authPairID + DSC ensures content isn’t just technically valid — it’s meaningfully accountable.

Roadmap Status

  • Complete Phase 1: Proof of Concept
    On-device signing, Manifest embedding, Android/iOS Cameras.
  • Complete Phase 2: Backend Trust
    Public Key Registry, Delegated Signing, Enhance app portability and features prior to launch.
  • In progress Post Rollout: Web Validation, app tweaks
    Release web validator, add minor features to Witness app (improved Settings page and Gallery functions).
  • Planned Phase 3: Editing Flow
    Integrity-preserving edits and Adobe Content Credentials compatibility.