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Steganography - Passing through the defenses

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Steganography is still considered to be a part of the obscure tools of secret agents and corporate spies.

However, steganography tools are widely available, and anyone can use them. Most of these tools are now available online. But a lot of systems currently perform some form of resampling or filtering of images.

This poses an interesting challenge - how survivable is steganography in filters?

This also gave us a great reason to publish another set of pictures (albeit cropped) of Lena Söderberg ;) Here is our original image


Proposed Counter-Steganography SystemThe filter system will need to be cost-effective, minimally intrusive and not prone to error. Since there may be many different steganography alghorithms, the filter system should not try to read such messages. Doing so will require an entire farm of filter servers. Instead, the systems will resort to a much simpler mechanism:
Modify all passing images so that the original hidden data is compromised.Use only minute changes to image…