🔒 StealthCanvas

To read your hidden message, the other person needs three things: the image file, the passphrase, and this same version of the app. To keep it working and private:

1. Send the image as a file, never as a photo. Use email attachment, Google Drive, or AirDrop "as file." Sending it through chat apps (WhatsApp, Messenger, Instagram, etc.) re-compresses the picture and destroys the hidden data. Quick check: what they receive should still be a .png of the same size.
2. Share the passphrase on a separate channel. Send the image one way and the password another (e.g. image by email, password by text). Don't put both in the same message.
3. The passphrase must match exactly — same letters, same capitalization. It both decrypts the message and tells the app where the data is hidden, so one wrong character finds nothing.
4. Both people need this same version of StealthCanvas. Older versions can't read images made by this one.

Note: encryption keeps the message unreadable without the password, and the data is hard to notice — but not impossible for an expert to detect. Treat this as "private," not "undetectable."