View Full Version : PDF DRM how do you know?


Gunnerp245
02-03-2009, 09:01 PM
How does one know whether a PDF file has DRM?
Gunner...

Jim Lester
02-03-2009, 09:38 PM
If you can open the PDF in Adobe Reader, go to Document Properties, security tab and look at "Security Method" if it says anything besides "No Security", it is encrypted (and DRM protected) using the named Security handler. Note: Adobe currently provides 4 security handlers (Password, Certificate, Live Cycle, and eBooks), and there are a multitude of 3rd party security handlers.

If you cannot open it in Adobe Reader, assuming it is a valid non corrupt PDF file, it is probably DRM protected.

If people are interested, I can give the true Geek answer of how to walk the PDF structure in a text editor to find out all of this information.

desertgrandma
02-03-2009, 10:10 PM
How does one know whether a PDF file has DRM?
Gunner...

Hello, Gunner, and welcome to MobileRead.

As you can see, we have knowledgeable people here, stick around and you'll learn lots more!

HarryT
02-04-2009, 04:53 AM
If you're asking how you can tell at the time you buy the book, it will, if it has DRM, generally be described as "Secure PDF" in the eBook store.

daesdaemar
02-04-2009, 04:46 PM
If people are interested, I can give the true Geek answer of how to walk the PDF structure in a text editor to find out all of this information.

I would love to know this... Knowledge is power...

Jellby
02-05-2009, 04:58 AM
Use "pdfinfo", it comes with poppler in my linux:

$ pdfinfo dantesinferno00dantuoft.pdf
Producer: Recoded by LuraDocument PDF v2.28
CreationDate: Thu Dec 6 09:34:21 2007
ModDate: Thu Dec 6 10:11:03 2007
Tagged: no
Pages: 372
Encrypted: no
Page size: 640 x 912 pts
File size: 37026003 bytes
Optimized: yes
PDF version: 1.5

Gunnerp245
02-07-2009, 12:13 PM
Thanks to all!
Gunner...
:thumbsup::thanks:

Ilcaa
12-11-2011, 12:18 PM
is there a way you guys can remove the 5 pictures you guys have as part of your profile? its annoying to have to scroll through so much white space in order to read the next post....

JSWolf
12-11-2011, 12:24 PM
is there a way you guys can remove the 5 pictures you guys have as part of your profile? its annoying to have to scroll through so much white space in order to read the next post....

What 5 pictures? Do you mean the avatars? If so, the answer is no. But you can turn off seeing avatars in your profile. You'll have to go look it up for yourself. I'm not doing it for you with that attitude.

HarryT
12-11-2011, 12:27 PM
is there a way you guys can remove the 5 pictures you guys have as part of your profile? its annoying to have to scroll through so much white space in order to read the next post....

Of course - I'm sure that everybody on the site will be delighted to remove their Avatars for your personal convenience.

Alternatively, you could go into your Control Panel, select "Edit Options", and in the "Thread Display Options" section, uncheck the "Show Avatars" box.

Jim Lester
12-11-2011, 12:49 PM
I would love to know this... Knowledge is power...

A little late in the reply, but I lost the thread until it got bumped :)

Open the file in a text editor.
Search for "/Encrypt"
- If you don't find it then your PDF is not encrypted

If you find it then you are most likely in the "Trailer" dictionary which is at the end of the file. There should be entries that look like:
/Root 74 0 R /Encrypt 96 0 R /Info 1 0 R

These specify which objects are the import one in the file.

To find a object search replace the R with an 'obj' and search (most likely backwards) in the file. So if I was searching for the Encryption Dictionary in the above example, I would search for "96 0 obj"

Which would get you something like
96 0 obj
<< /Filter /Standard /V 2 /R 3 ....
>>

The interesting bit is the value for /Filter - in this case it is /Standard meaning the file uses the 'Standard' security handler which is Password Protection.