-1

I see some pdf files have no protections, but when you try to copy and paste text it appear as unredable 

"┤xDn║if|d├gDF"Ti&cD╬lh d FÁhis~n ╗xd f«"d┤ffih »h"

And the images are also not copied (only print screen works).

How can one create a pdf that is 'protected' but without password. or visible restrictions ?

Anonymous
  • 167
  • 11
  • 2
    This is not really a protection, just using a font enconding that is weird and probably not event meant to be a protection. – Stefan Hegny May 25 '16 at 13:59

2 Answers2

1

For text you can use fonts with Identity-H encoding and no ToUnicode cmap (or a dummy one).

For images you can use a pattern to display them. Some viewers cannot copy images from patterns but this is just a hack, not a real protection.

Mihai Iancu
  • 1,818
  • 2
  • 11
  • 10
  • This depends entirely on the PDF library you use to create the PDF files. For example our library XFINIUM.PDF includes the PdfUnicodeTrueTypeFont class which creates an IdentityH encoded TrueType font. This class has the EnableTextCopy property which when set to false disables the creation of the ToUnicode cmap for that font. – Mihai Iancu May 25 '16 at 19:45
1

Another option is don't create PDFs out of TEXT, rather in your image editor like Photoshop create an IMAGE with your photos and text. Save that as a gif/png/jpg whatever is appropriate. Then embed that into the PDF instead. Since its a flat image, no characters are stored in the PDF.

imvain2
  • 15,480
  • 1
  • 16
  • 21
  • Thank you. But OCR acn turn it into text, wouldnt it. And photoshop is not very friendly with lots of pages. – Anonymous May 25 '16 at 17:01
  • Anonymous, on the other hand OCR also can turn a screenshot of what you thought of as "protected" PDF into text - it's just as safe. – Stefan Hegny May 25 '16 at 18:42
  • @Anonymous, as stefan pointed out, you are really stuck with either: use my suggestion, which stops copy and pasting, but doesn't stop OCR or use the strange encoding which stops copy and pasting but also doesn't stop OCR of screenshots. And in Bridge, you can merge multiple documents into one PDF. But photoshop was just an example as its one of the most popular image editors. – imvain2 May 25 '16 at 19:45