aka Digital Rights Management

technology that attempts to protect Intellectual Property, esp Digital Media

  • tends to fail over time - see history of software protection, e.g. dongles

  • tends to have Side Effect-s of annoying legitimate customers

interesting idea: Social DRM

breaking EBook DRM (so you can use an open reader)

Feb'2015: Barnes And Noble stripping has been failing lately

  • old code was failing with {{{ Traceback (most recent call last): File "ignobleepub_cl.py", line 119, in sys.exit(cli_main()) File "ignobleepub_cl.py", line 107, in cli_main decryptor = Decryptor(bookkey[-16:], encryption) File "ignobleepub_cl.py", line 48, in init self._aes = AES.new(bookkey, AES.MODE_CBC) Value Error: Key cannot be the null string }}}
  • found newer version of script - same results (maybe msg AES improper key used)
  • tried the DeDRM app, get error msg command exited with a non-zero status
    • some comments in that page suggested using Nook Study app to download books
      • that has changed to Yuzu https://yuzu.com/nsdownload
      • downloaded, launched - used existing library of books
      • deleted newest book, let app re-download it. DeDRM failed with same msg
  • try the "newer" script on the new book file, get new failure {{{ Traceback (most recent call last): File "ignoblepub_cl2.py", line 319, in decryptBook outf.writestr(zi, decryptor.decrypt(path, data)) File "ignoblepub_cl2.py", line 233, in decrypt data = self.decompress(data) File "ignoblepub_cl2.py", line 223, in decompress bytes = dc.decompress(bytes) error: Error -3 while decompressing: invalid distance too far back }}}

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