NSA provides list of patents it's willing to share with public

[Steve Kinney]

On 07/07/2017 04:17 PM, Ryan Carboni wrote:

> Patent  9,525,866, from 2016, is anti-camera forensics. Time to go back
> to film! (or maybe just resize it to 50% and save it as a rather lossy JPEG)

I would not trust that very far:  Signatures from hot pixels may remain
visible to the naked eye as well as statistical analysis, and variations
in color registration across larger areas of the sensor would survive.
A camera signature does not need to be unique to be very valuable to an
adversary who has other means at hand to narrow the field of candidates
for creator of this or that image of interest.

Conversion to a vector format with the aid of an auto-trace program
should work reliably, at the cost of a /massive/ loss of resolution.

If the photo needs to still look like a photo when you're done
sanitizing it, the GMIC filter pack's tool set may be useful, with
effects like bilateral smoothing etc. that wipe out small scale noise
signatures.  Conversion to grayscale, or or reducing color resolution
and changing RGB balance would also be a good idea.  Exporting sanitized
images in an indexed format with a limited size palette (i.e. GIF) would
be helpful. But no matter what, if you remove enough detail to
confidently disassociate the photo from the camera, image quality will
suffer quite visibly.

One's method for altering photos to disassociate them from individual
camera sensors would have to change often or it would create a trail of
its own.

:o)





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