PrivateMark: Photo Watermark

PrivateMark turns any photo or document you share into a copy you can trace. Before you send a file, it weaves in an invisible watermark that's unique to each recipient — entirely on your device. If that file ever leaks, feed the copy you found back to the app and it tells you exactly whose copy it was, with statistical confidence. No servers. No accounts. Nothing ever leaves your device. — HIDDEN PHOTO — Send a photo that everyone sees as an ordinary cover image. Your trusted contact opens it in PrivateMark and sees the real photo you actually sent — nobody else can, because it's protected with AES-256 encryption only the two of you share. Pair once, in person; then send it privately as a file, or as a normal photo through any chat. Concealment plus real encryption — and we're honest about what it does and doesn't do. — PHOTOS AND DOCUMENTS — Protect photos, PDFs, and Word and PowerPoint files. For documents the mark lives in three independent layers: every embedded image, the text itself (it even survives being copied and pasted into a new file), and a keyed fingerprint in the file. A leaked copy points back to one person even after it's forwarded or re-exported. — BUILT TO SURVIVE THE REAL WORLD — The watermark isn't metadata that a screenshot would strip — it lives in the content. In our lab it survives WhatsApp and iMessage recompression (~99%), screenshots (~97%) and cropping (~99%), all while staying invisible to the eye (~41 dB PSNR). — HOW IT WORKS — 1. Protect: pick a photo or document, name the recipient ("Maria", "Legal", "Board"). 2. Share: send the protected copy through any app. It looks identical. 3. Investigate: found it somewhere it shouldn't be? Import the copy and PrivateMark names the recipient whose copy leaked. — PRIVATE BY DESIGN — • No servers — watermarking and attribution run entirely on your device. • No accounts — nothing to sign up for, nothing to breach. • Your recipient list is encrypted at rest and syncs only through your own private iCloud. • The shared copy keeps its ordinary filename — nothing signals it was protected. — HONEST ABOUT LIMITS — PrivateMark doesn't crawl the internet for you — you bring the file, it names the copy. Some copies are too degraded to name the recipient (tiny thumbnails, a photo of a screen, or a screenshot of a text-only document). In those cases it still recognizes the file as yours and shows everyone you sent it to, so you can narrow things down. — PRICING — Investigating leaks is always free. A free trial lets you protect a few shares; PrivateMark Pro unlocks unlimited protection on iPhone, iPad and Mac with one purchase. Privacy: https://privatemark.app/privacy Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/