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A comment on Elsevier embeds a hash in the PDF metadata that is unique for each download. Parent comment

Re:Elsevier embeds a hash in the PDF metadata that is unique... by matheusmoreira on Wednesday January 26, 2022 @06:36AM (#30084295)
This isn't a watermark though. This is giving different people different content. Watermarks don't change the content.
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Re:Elsevier embeds a hash in the PDF metadata that is unique... by aembleton on Wednesday January 26, 2022 @07:14AM (#30084594)
But Stenography does; just in ways that are imperceptible to humans.
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Re:Elsevier embeds a hash in the PDF metadata that is unique... by matheusmoreira on Wednesday January 26, 2022 @07:26AM (#30084681)
Moving words around is perceptible to humans though. It can even destroy the meaning of content.
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