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Spymarks, not Watermarks

698 points · 171 comments · possibilistic

  1. Retro_Dev · · focus · HN ↗
    Spymarks just seem like another word for <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Steganography" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Steganography. On that note, one way we can prevent it is to assert that all our content is byte-for-byte identical with the last known trusted stage of what we have produced (for example: a camera we are certain does not watermark, an image editor we are certain doesn&#x27;t watermark, an image compressor we are certain can&#x27;t watermark, etc). One vector that I am particularly concerned about is social media. Most images and videos uploaded to most social media is re-compressed by the target platform. This is a door to tracking that is far too easy for social media platforms to open. They might rationalize it (if discovered&#x2F;announced) by saying that our memes won&#x27;t be reposted, images or work stolen, etc... but honestly I&#x27;d rather my work be stolen than tracking information inserted in there. Oh, we also have stuff which is way more secure, like time-stamped cryptographic signatures.
    1. dragonwriter · · focus · HN ↗
      Spymarks an application of steganography, not a different name for it.

      &gt; On that note, one way we can prevent it is to assert that all our content is byte-for-byte identical with the last known trusted stage of what we have produced

      That doesn&#x27;t help with things like the typical use of SynthID where the spymarking is done by the same process generating the content, so there is never a clean comparator. (It also wouldn&#x27;t be useful anytime it is inplemented as part of a transformation—compression, etc. —step, for the same reason.)

      1. Normal_gaussian · · focus · HN ↗
        Additionally, verifying that your generator doesn&#x27;t add such a mark is practically impossible for the majority.
        1. sitkack · · focus · HN ↗
          When someone else controls distribution, they also control the spark, each request could serve up a different payload. So innocuous images could encode ids, tracking receivers as well as originators.
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