How to remove protection from this PDF

(http://stream-recorder.com/forum/showthread.php?t=11120)

How to remove protection from this PDF

Hi to all;

I have read a lot of threads posted in this section but I could not find an answer.

I will make it simply:

I have this PDF (it is an ebook)
http://www.mediafire.com/?uy7i0uqljjw0qnx

I can not read this book using ADE, Nook, Kindle ........ long list
Also I use Calibre and INEPkey phyton for removing protection but nothing happens (no output file is created)
Also I tried using some programs for repair PDFs ( BUT I know this is not a corrupted PDF because it was obtained directly from a root directory), like Advanced PDF Repair and Advanced Ebook Processor software

A friend of mine told me about this site and told me that you have all the answers about PDFs

Please help me to solve this mystery

Thanks in advance
Sincerely, Nemesis123

Re: How to remove protection from this PDF

I want to expand some information:

1. This is NOT AND OLD ENCRYPTED PDF, so this is not the case of:

Quote:

I have an old encrypted PDF file that won’t open in Adobe Digital Editions, how can I remove the DRM?
If your PDF ebooks cannot be read in Adobe Digital Editions, the tools here cannot help. They are probably encrypted using the Content Server 3 (or earlier) methods which Adobe no longer support, not even to allow conversion to Content Server 4 (AKA Adobe Digital Editions).

2. But we know that unless a PDF is licensed with a key, we cannot open/decrypt it.

The file in above link is not licensed with a key.

So without a key, how can we remove the lock?

I will be very grateful if the most experienced members give opinions

Thanks a lot in advance