Don't Trust a Scan You Didn't Forge Yourself

#copy#scan#security#talk#xerox

A really interesting talk that shows a (rather amusing, dramatic) bug in Xerox copiers. In short: Xerox copiers cache similar image patches and then reuse them over and over when printing. If two image patches are very similar (very, very similar), the copier assumes they are the same patch and replaces the similar patch with the cached one. You can read David Kriesel's blog post about the talk here. The talk is on YouTube and explains the problem very clearly. Watch the video