[SOLVED] Add copy protection to PDF?

Cenobite · 10-27-2010, 06:43 AM

I'm setting up a fileserver for a client which will host their client invoices. They're looking for a system whereby invoices can be converted from RTF to PDF with copy protection (no right click / copy-paste). In addition to this I'm thinking of using a one-way hash to verify document integrity.

Are there any command-line utilities for Linux which allows adding this kind of copy protection / DRM to pdf documents?

Thanks!

fbobraga · 10-27-2010, 06:51 AM

Quote:

Originally Posted by Cenobite

(...) PDF with copy protection (no right click / copy-paste).

It's a Adobe-PDF specific feature (and not part of PDF format specification), as far as I know

Guttorm · 10-27-2010, 06:59 AM

pdftk can do this.

For example:

pdftk plain.pdf output drm.pdf owner_pw someSecret encrypt_128bit allow printing

This can be printed, but no copying from the document if you don't know the password.

See man pdftk for more details.

Guttorm · 10-27-2010, 07:36 AM

Quote:

It's a Adobe-PDF specific feature (and not part of PDF format specification), as far as I know

It is part of the PDF specification. But of course it's not very hard to modify an open source reader. Some time ago I read about somebody changing xpdf so you could for example copy content without the password. Such a program is legal, but you cannot call it a PDF reader since it doesn't follow the specification.

Cenobite · 10-27-2010, 08:32 AM

pdftk looks like just the ticket!

Thanks, Guttorm!

Quote:

Originally Posted by Guttorm

pdftk can do this.

For example:

pdftk plain.pdf output drm.pdf owner_pw someSecret encrypt_128bit allow printing

This can be printed, but no copying from the document if you don't know the password.

See man pdftk for more details.

fbobraga · 10-27-2010, 08:35 AM

thanks for the info :P