ProofMode: Verified Witnessing

BETA WARNING: This is an early release and has not been fully audited technically or tested in court or other legal proceedings.

ProofMode is light, minimal "reboot" of our full encrypted, verified secure camera app, CameraV ( Our hope was to create a lightweight, almost invisible utility, that you can run all of the time on your phone, that automatically extra digital proof data to all photos and videos you take. This data can then be easily shared through a "Share Proof" share action, to anyone you choose.

ProofMode is an open-source project:


* Run all of the time in the background without noticeable battery, storage or network impact
* Provide a no-setup-required, automatic new user experience that works without requiring training
* Use strong cryptography for strong identity and verification features, but not encryption
* Produce "proof" data formats that can be easily parse, imported by existing tools (CSV)
* Do not modify the original media files; all proof metadata storied in separate file
* Support both full "proof" data generation, as well as more simple sha1/sha256 hash and PGP signature of media files
* Do not require a persistent identity or account generation


* Some icons were used under the APL 2.0 license from the Google Material Design Icon library:
* The App Intro library is used under the APL 2.0 license:
* Spongy Castle uses the same adaptation of the MIT X11 License as Bouncy Castle.:
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26 total

What's New

* Added support for Android 4.1 and up again
* Fixes for Samsung Galaxy S6
* Updates for Spanish, French
* Shares ZIP with full media sharing
* Add Cell Tower lookup
* improvements to proof generation
* multiple fixes for file permission, geo location and other permission issues
* Improve display of the date/time in proof message
* Just display the short version of the key
* generate proof data at time of share if it doesn't exist
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Additional Information

January 25, 2018
Current Version
Requires Android
4.1 and up
Content Rating
Offered By
The Guardian Project
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