Foil Pics allows you to encrypt some pictures from the gallery with a password stronger than the lock code. Strictly speaking, each picture is encrypted with a unique random 256-bit AES key which in turn is encrypted with an RSA key which in turn is encrypted with your password. If the bad guys get your encrypted pictures, they would have to crack the AES key (different for each picture) or the RSA key (shared by all pictures but harder to crack) in order to extract the content. If they get the encrypted RSA key as well, then they can brute force your password. So in the end, the encryption is as strong as your password.
The format of the encrypted file is described here.
The RSA key is stored in ~/.local/share/foil/foil.key - you can copy it from one device to another. Using the same RSA key on different devices, protected with different passwords, is actually not such a bad idea. If you forget the password, you can use the backup key to decrypt the images, assuming that it has a different password that you still remember.
Source code: https://github.com/monich/harbour-foilpics
- Support for multiple selection
- Encrypted images can be grouped
- Dutch and Polish translations
- Navigation between images in fullscreen mode
- Swedish translations
- German translations
- Details page for encrypted and gallery images
- Title of the encrypted image is editable (via details page)
- French translations
- Initial version