PrivateMark is a privacy and security tool created by software engineer Jose Blaya, designed to help users protect shared media and identify data leaks. Operating entirely on-device, the application eliminates the need for user accounts, external servers, or cloud dependencies, ensuring complete user privacy.

The tool provides two core functionalities:

Leak Tracing: Before sharing sensitive photos, PDF documents, Word files, or PowerPoint presentations, PrivateMark embeds an invisible, recipient-specific watermark. If a document or image is later leaked, feeding the file back into PrivateMark instantly reveals which recipient's copy was shared.
Hidden Photos: PrivateMark allows users to hide sensitive photos behind an innocent cover image. Shared cover images appear completely normal to standard viewers, but trusted contacts can open the file within PrivateMark to uncover the real photo, secured with AES-256 encryption.

Pros of PrivateMark

Operates completely on-device with no servers or accounts required
Embeds invisible per-recipient watermarks across photos, PDFs, Word, and PowerPoint files
Instantly identifies the specific recipient responsible for a leaked document
Uses strong AES-256 encryption to hide images inside cover photos

Cons of PrivateMark

Revealing hidden photos requires the recipient to open the file in PrivateMark
Limited metadata regarding advanced administrative controls or pricing tiers

Frequently Asked Questions

How does PrivateMark identify document leakers?

PrivateMark embeds an invisible, per-recipient watermark into photos, PDFs, Word, or PowerPoint files prior to sharing. If a file leaks, feeding the leaked file back into PrivateMark reveals whose copy it was.

Does PrivateMark upload my files to a server?

No. PrivateMark operates completely on-device without using external servers or requiring account registration.

How does the Hidden Photo feature work?

The Hidden Photo feature lets you send a normal-looking cover picture. When a trusted contact opens that picture inside PrivateMark, it decrypts and reveals the actual photo using AES-256 encryption.