Slashdot Reader Builds a Photo-Verification App for iPhones (nerds.xyz)
(Sunday August 09, 2026 @09:59PM (EditorDavid)
from the phoning-it-in dept.)
Long-time Slashdot reader [1]BrianFagioli is [2]announcing that he's released a new iPhone app that creates a cryptographic witness for photos without uploading the original image.
> The app hashes the file, signs the hash using a dedicated identity stored in Apple Keychain, and publishes the witness to Nostr relays while keeping the photo inside the app unless the user chooses to export it.
>
> Rather than trying to determine whether a scene was genuine, the app — named Veridenz — answers a narrower question, by verifying whether a photo file matches the one that was originally witnessed. Users do not need a Nostr account because the app creates its own signing identity, keeping private documentation separate from a public Nostr profile.
"The developer does not collect any data from this app," says [3]its page in Apple's iPhone store . The app's tagline is "Capture. Prove. Verify."
[1] https://www.slashdot.org/~BrianFagioli
[2] https://nerds.xyz/2026/08/veridenz-verify-photos-nostr/
[3] https://apps.apple.com/us/app/veridenz/id6796029293
> The app hashes the file, signs the hash using a dedicated identity stored in Apple Keychain, and publishes the witness to Nostr relays while keeping the photo inside the app unless the user chooses to export it.
>
> Rather than trying to determine whether a scene was genuine, the app — named Veridenz — answers a narrower question, by verifying whether a photo file matches the one that was originally witnessed. Users do not need a Nostr account because the app creates its own signing identity, keeping private documentation separate from a public Nostr profile.
"The developer does not collect any data from this app," says [3]its page in Apple's iPhone store . The app's tagline is "Capture. Prove. Verify."
[1] https://www.slashdot.org/~BrianFagioli
[2] https://nerds.xyz/2026/08/veridenz-verify-photos-nostr/
[3] https://apps.apple.com/us/app/veridenz/id6796029293