Prove a Photo Wasn't Edited | Prooflens
Frequently asked questions
- How does Prooflens prove a photo wasn't edited?
- Three layers. A local SHA-256 manifest of the image, an RFC 3161 trusted timestamp, and a Bitcoin blockchain anchor via OpenTimestamps. Editing the photo breaks the hash, and the break is detectable.
- What actually leaves my phone when I take a proof photo?
- Only the SHA-256 hash. Your photos never leave the device — there is no cloud backup and no account.
- Can I verify someone else's Prooflens evidence without trusting the app?
- Yes. Verification runs fully on-device, so you can check the evidence yourself rather than relying on the app that produced it.
- Is there a court-style document I can export?
- Pro exports a .zip plus a PDF legal statement documenting the evidence and its anchoring status.
The short answer
A photo has no built-in memory of itself. Any file can be edited, and a plain JPEG carries nothing that records what it looked like when it was taken.
Prooflens fixes that by making each capture carry its own evidence:
- A local SHA-256 manifest of the image, computed on your device
- An RFC 3161 trusted timestamp, so the hash has a time a third party vouches for
- A Bitcoin blockchain anchor via OpenTimestamps, so the timestamp itself cannot be quietly rewritten
Edit the photo and the hash stops matching. That is the whole mechanism — and it is why the question "was this edited?" stops being a matter of opinion.
Why three layers rather than one
A hash alone proves the file has not changed since the hash was made. It does not prove when the hash was made, or that someone did not simply make a new hash of an already-edited file.
The timestamp answers the first question. The blockchain anchor answers the second: anchoring the timestamp to Bitcoin makes it publicly verifiable and permanent, so it cannot be backdated or silently replaced.
Together they close the gap that a single layer leaves open.
What leaves your phone
Only the SHA-256 hash. Your photos never leave the device — no cloud backup, no account, no tracking. Verification also runs fully on-device, which means you can check someone else's evidence yourself rather than trusting the app that produced it.
For evidence you need to share, Prooflens can produce anonymous evidence with the device serial stripped.