Two questions about authentication and photo handling came up recently, including whether I use fingerprints and whether the system preserves separate original and working copies.
User authentication on the unit uses a username and PIN. Photo verification starts with the JPEG the user accepts.
Authentication on the touchscreen and the network dashboard work the same: username and PIN, with a hash comparison on the back end.
The mobile app is still pre-release. Right now you log into the unit, then pair the phone to it with a QR code. Once paired, the phone generates a private key for whoever's logged in, and every app request after that uses that key.
One of the questions specifically mentioned biometric fingerprint authentication on the phone. I'm not using that to verify the user yet. It's a good idea and I'm going to look at adding it.
For evidence photos, the user approves the photo and the accepted JPEG gets hashed at that point. When the phone uploads it to the main unit, the hash is verified, and the system records acceptance, upload-receipt, and verification times.
A matching hash provides a check that the uploaded JPEG matches the file that was accepted and hashed. That check starts at acceptance. It doesn't establish what happened to the image before hashing, and the recorded acceptance time shouldn't be treated as a separate record of the instant the shutter was pressed.