An anonymous reader shares a report: A Polish academic is accusing Google of trying to patent technology he invented and that he purposely released into the public domain so companies like Google couldn't trap it inside restrictive licenses. The technology's name is Asymmetric Numeral Systems (ANS), a family of entropy coding methods that Polish assistant professor Jarosaw (Jarek) Duda developed in the early 2000s, and which is now hot tech at companies like Apple, Google, and Facebook, mostly because it can improve data compression from 3 to 30 times. Duda says that Google is now trying to register a patent that includes most of the ANS basic principles. Ironically, most of the technology described in the patent, Duda said he explained to Google engineers in a Google Groups discussion from 2014. The researcher already filed a complaint, to which WIPO ISA responded by calling out Google for not coming up with "an inventive contribution over the prior art, because it is no more than a straightforward application of known coding algorithms." A Google spokesperson refused to comment, and the mystery remains surrounding Google's decision to patent something that's in the public domain since 2014.