Question

I need to protect images embedded in a swf file.

I’ve noticed Swf Encrypt scrambles the images, like so:

How is something like this achieved ? How does image scrambling work ?
I’ve noticed the image is stored a bitmap. Not sure how information is stored.

I imagine it would be possible to use something like AS3SWF to access the
content of a swf, but what would I need to change for the image swf tags ?

I don’t know much about security/obfuscation/encryption, so any tips will be handy.
The programming language for this shouldn’t matter much.

Answer 1

I’m going to go out on a limb and say that the image scrambling works similar to how plain text looks ‘scrambled’ once it’s encrypted – if you apply the right cipher to the seemingly randomly coloured pixels in that example image, each pixel becomes the correct colour, revealing the image.

That cipher or key to unscrambled it must be somewhere accessible to the .swf, so that whenever the .swf loads that image, it pulls it apart pixel-by-pixel, checks that against the key, and then rebuilds the image.