3 ms·

Even if I don't like the practice of charging so much for scientific papers, I must say that watermarks are the best form of DRM. You own the file, you can prin

Even if I don't like the practice of charging so much for scientific papers, I must say that watermarks are the best form of DRM. You own the file, you can print it, you can save it. That's a stark difference from most schemes going around these days

jmnicolas 5y ago
Except when the watermark is right in the middle of the page and harms reading flow. I had the case a few months ago very frustrating. The PDF was encrypted, I couldn't remove the watermark.
- SSLy 5y ago
  There are open source apps that ignore PDF "encryption"
  - newaccount74 5y ago
    qpdf --decrypt infile.pdf outfile.pdf
  - criddell 5y ago
    Where do they get the key from?
    - oauea 5y ago
      No key needed, else you'd need one for viewing the content too.
      - criddell 5y ago
        You do need a key just to view. Acrobat 9 and above uses AES with a 256-bit key. I think it's all built on Adobe's Digital Editions technology.
  - jmnicolas 5y ago
    Since I wanted to read it asap, I didn't invest too much time trying to defeat it but if you have something reliable I'm all ears for next time. From what I understand Adobe Acrobat might have done the job, but it's an expensive software and I refuse to run cracks anymore.
    - Isthatablackgsd 5y ago
      Calibre with DeDRM plugin can remove the encryption and DRM. Done this few years ago for my undergrad, it works well. Just import the PDF to Calibre and Calibre will handles it from there (as long you have the DeDRM plugin). It depends on the encryption being used. If it is coming from Abode Digital Edition, then DeDRM plugin need your credential to decrypt it and convert the file without encryption. It needs your credential since ADE ties the encryption to your credential, so it need that to get the key to decrypt it. First setup will be a while but once it is properly setup, it will takes seconds to decrypt the encrypted/DRMed PDFs. Even you can print the file without worrying if it will be in garbled mess.
- akvadrako 5y ago
  Watermarks don't even have to be visible. They could do things that survive re-encoding but are too subtle to see. For example adding a few slightly off color pixels to random letters on the page.
  - jmnicolas 5y ago
    In this case I think the goal is to discourage publishing the PDF since your email will be visible to all the people that downloads it. I wouldn't mind them protecting their work if it didn't harm readability and if the report was worth the money I paid (but it's another problem).
matheusmoreira 5y ago
> You own the file Probably not. I bet they're just "allowing" you to have the file.
- Buttons840 5y ago
  He means you control the file, and have the ability to copy it and open it on any device, and the legal "owner" of the file doesn't have the power to stop you by any common means.
- contravariant 5y ago
  Well as far as I'm concerned they only own the distribution rights. They've got no business messing with my files or the system(s) it's on. Though that's my moral standpoint, from a legal standpoint the situation may well be FUBAR, at least in the U.S.

jmnicolas 5y ago

Except when the watermark is right in the middle of the page and harms reading flow. I had the case a few months ago very frustrating. The PDF was encrypted, I couldn't remove the watermark.

SSLy 5y ago
There are open source apps that ignore PDF "encryption"
- newaccount74 5y ago
  qpdf --decrypt infile.pdf outfile.pdf
- criddell 5y ago
  Where do they get the key from?
  - oauea 5y ago
    No key needed, else you'd need one for viewing the content too.
    - criddell 5y ago
      You do need a key just to view. Acrobat 9 and above uses AES with a 256-bit key. I think it's all built on Adobe's Digital Editions technology.
- jmnicolas 5y ago
  Since I wanted to read it asap, I didn't invest too much time trying to defeat it but if you have something reliable I'm all ears for next time. From what I understand Adobe Acrobat might have done the job, but it's an expensive software and I refuse to run cracks anymore.
  - Isthatablackgsd 5y ago
    Calibre with DeDRM plugin can remove the encryption and DRM. Done this few years ago for my undergrad, it works well. Just import the PDF to Calibre and Calibre will handles it from there (as long you have the DeDRM plugin). It depends on the encryption being used. If it is coming from Abode Digital Edition, then DeDRM plugin need your credential to decrypt it and convert the file without encryption. It needs your credential since ADE ties the encryption to your credential, so it need that to get the key to decrypt it. First setup will be a while but once it is properly setup, it will takes seconds to decrypt the encrypted/DRMed PDFs. Even you can print the file without worrying if it will be in garbled mess.
akvadrako 5y ago
Watermarks don't even have to be visible. They could do things that survive re-encoding but are too subtle to see. For example adding a few slightly off color pixels to random letters on the page.
- jmnicolas 5y ago
  In this case I think the goal is to discourage publishing the PDF since your email will be visible to all the people that downloads it. I wouldn't mind them protecting their work if it didn't harm readability and if the report was worth the money I paid (but it's another problem).

matheusmoreira 5y ago

> You own the file Probably not. I bet they're just "allowing" you to have the file.

Buttons840 5y ago
He means you control the file, and have the ability to copy it and open it on any device, and the legal "owner" of the file doesn't have the power to stop you by any common means.
contravariant 5y ago
Well as far as I'm concerned they only own the distribution rights. They've got no business messing with my files or the system(s) it's on. Though that's my moral standpoint, from a legal standpoint the situation may well be FUBAR, at least in the U.S.