Declan reports that Senators McCain and Schumer have proposed the SAFE act, which would create a national database of child porn images - or I'm guessing, simply require that the FBI make their own database public. ISPs would be given access to this database, and would be required to screen traffic and alert the authorities of any user who transmits/hosts an image that matches a fingerprint in this database.
Once the infrastructure is in place for them to compare hashes of child porn, it won't be too difficult for them to start comparing hashes of music, copies of dissident literature, photographs of dead soldiers in Iraq, anti-Scientology documentation, or anything else that someone with their hand in a Senator's pocket doesn't like.
To combat against this evil intrusion into our private Internet behavior, I now introduce 'broken glass'. It is a perl script that when given an image file, will change 1 pixel's red component by /- 1. It's not enough for the human eye to see, but it will make the MD5/SHA1 hash fingerprint of the image be completely different.
This is an interesting idea. The counter attack to this would be break a file into many small pieces and hash each one. Then, for every image that comes across the wire, break it into pieces, hash them, and if a certain threshold of them match, its child porn.
Of course the counter-counter attack would be to randomly select some ratio of pixel locations based on the resolution of the image and toggle the red component on them.
I'm not trying to enable child porn. Those people should all be shot. However, its interesting to think about how data can be modified to survive a hostile network that is looking for certain traffic, and yet still be readable on the other side.
You can randomly toggle image pixels, what about plain text? Well, Spam has shown that the human brain can "correct" misspellings, repeated letters, or words in 1337 speak while reading. And then you have whitespace...
RE: Thought Crime