Two copies of one photo, each hiding a different name

We wanted to share one photo privately with two people, Alex and Sam, and know whose copy it was if it ever turned up elsewhere.

• Alex's copy.
• Sam's copy.

What changed

• Nothing you can see. To the eye, the two copies are identical.
• What each one hides. With snapWONDERS Vaultify, we hid "Copy for: Alex" in one and "Copy for: Sam" in the other, each as a small picture protected by our password.
• What the password shows. Revealing Alex's copy gave back the name:

If that copy turned up somewhere it shouldn't, this is how you'd know whose it was.

The limit: the mark survives when the file is passed on as a file, by email, download or file share. A copy re-compressed by a social platform, or screenshotted, will usually have lost it. Your originals are the proof that survives everything.

Go deeper

• What works and what doesn't: How to protect your photos from being copied
• Hide a name in your own photo