What makes a photo evidence rather than a picture
An ordinary photo can be edited and re-saved and nobody can tell. Where and when it was taken can be changed in seconds by anyone with a free tool. That is not a flaw in your phone; it is simply what an image file is. The morning after something happens, what you are holding either proves itself or it doesn't.
What a sealed capture carries
| Place | The town and state, resolved at the shutter |
|---|---|
| Coordinates | Latitude and longitude, to six decimal places |
| Time | Date and time to the second |
| Fingerprint | SHA-256 of the image as captured |
| Encryption | AES-256-GCM |
| Key held by | Your phone. Only your phone. |
Why the fingerprint matters
A SHA-256 fingerprint is a short string derived from the file. Change one pixel and the string changes completely. Taking it at the moment of capture means there is a record of exactly what came off the sensor, before anyone — including us — could have touched it.
So when you hand the photo over later, the person receiving it does not have to take your word for anything. They re-compute the fingerprint themselves and compare. Either it matches the one recorded at the shutter, or the file has changed since. There is no third answer.
Why the encryption matters
The capture is encrypted on the phone, with a key kept in the device's keystore, before anything leaves it. We never hold that key. This is what "zero-knowledge" means in practice: the vault is ours, the contents are not readable by us, and that is a property of the design rather than a promise about our behaviour.
Handing it to police, a lawyer or an insurer
You export it. The export carries the untouched original and the fingerprint taken at capture, so the recipient can verify it independently without needing our app, our servers or our cooperation.
Export is free and stays free whether you are subscribed or not. Evidence you captured is yours; holding it hostage behind a lapsed subscription would defeat the purpose of collecting it.
What this is not
A sealed capture proves that a particular image existed at a particular place and time and has not changed since. It does not prove what the image means, and it is not a substitute for legal advice. What it removes is the argument about whether the photo itself can be trusted.