Can I avoid image post-processing during media posts?


#1

Over the last couple years, I’ve built a secure chat application on top of the public Twitter API that data-mines timelines to provide private communications. My solution was built using steganography, among other things. Recently I noticed that Twitter is post-processing the PNG files, which at first made sense because I saw the alpha channel was being stripped. Unfortunately, the alpha isn’t the only thing being changed and consequently the private data in my images is now being discarded.

Does anyone know of any way to avoid this post processing on uploaded media content?

Thanks.


#2

What specific information are you expecting to find in images shared on the Twitter platform?


#3

My secure chat application encrypts private messages and then uses custom steganography in either JPEG or PNG files to store the messages inside the photos I post.

In other words, I’m storing the secret messages in the color information of the images.

Although I have a solid solution for JPEG, it has never worked on any site (Twitter, Facebook) I’ve tried because I assume JPEGs are always re-saved when they are received.

On the other hand, up until about three weeks ago, I’ve been successfully using Twitter for secret messaging using PNG files (probably at least 9 months). I wrote a custom PNG reader/writer that stores extra data in the RGB colors. When I send up an RGB file with precise colors, I don’t receive those same colors back when I look for it later. As I mentioned before, I noticed that you now flatten the image, removing the alpha, which I completely understand, but I wasn’t clear on the adjustment to the color information and was wondering if there is any way to avoid that in what I post.

Thanks for the quick response.

Fran


#4

Thanks a lot! It appears it is working again.