Tiling and progressive compression for leaking images

[chris-belcher]

Tiled printing an image before encrypting for use with darkleaks is a good idea. This could easily be done now by using photoshop.

Another idea to use progressive compression. To recap the "Progressive JPEG" format, is where data is compressed in multiple passes of progressively higher detail. This is ideal for large images that will be displayed while downloading over a slow connection, allowing a reasonable preview after receiving only a portion of the data.
Originally used to improve user experience when web browsing on slow connections, progressive compression could be useful for darkleaks. The different levels of image detail are separately encrypted and unlocked. Paying more money grants you access to more detail. Paying for only the lowest detail level allows the buyers to get an idea of what they're paying for.

Obviously the idea can easily be extended for video and audio, at least for music. For audio involving speech, progressive compression may not matter much. Evidence of a war crimes plot is understandable whatever the bitrate of recording, it doesn't need to be studio-level quality. Presumably in that situation the leaker will release a written transcript along with the audio file.