Re: PDF is blocked for printing, etc. OK for acroread (it behaves as expected), but KPDF allows me to print it, even if it is protected! Why?

[Merciadri Luca <Luca.Merciadri@student.ulg.ac.be>]

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Sorry, my last message was actually rejected by the moderation robot
(if this is a robot).

Vincent Danjean <vdanjean.ml@free.fr> writes:

> On 19/04/2010 17:32, Merciadri Luca wrote:
>> Sjoerd Hardeman wrote:
>>> Pdf "anti-features" are fake security. Don't trust on them, never.
>> And what do you suggest if one wants some real protection _and_ the
>> benefits of a format like PDF? Thanks.
>
> If you have free software (ie software you have the sources and are able
> to recompile) and if you can get the information on the screen, then it is
> only a matter of programmation to be able to have it on printer. So,
> free software readers that forbid printing can be (more or less) easily
> circumvented (and the patch to do this will be done and available on
> internet). So why would the authors of such readers want to program this
> at first time.
>
> If you want to avoid printing, you need to fully control the whole chain
> (ie TPA, ...) AND the terminals (ie, if you can show it on screen, some
> classic 'print-screen-to-file' and graphical software can be used to
> print the document, or even camera and image post-processing).
>
> For now, the only domain where such restrictions works partially are
> HD-DVD (and its possible it is already broken). This is possible because
> it is expensive to acquire good quality video data (ie recording what
> is diffused by a secure HD player on screen by a camera will have
> no really good quality). This would not work for audio data (at least,
> until the decoder is not embedded into brain ;-) ) because it would
> be easy to reacquire good quality data from a line-out.
/
>
> So, what would be the use case to allow a someone to read the information
> but not print it ? In any case, printing it would be more or less convenient
> but it will always be possible if it is displayed on screen (even
> with Acrobat Reader)
As I explained before (or in the same thread in linux.debian.user),
this is more a management (i.e. human) problem than a technical
problem. It sometimes happens that you want to show something but
without giving the others the possibility to do what they want with
what you show them. I here suppose that the `others' are quite beginners.

- -- 
Merciadri Luca
See http://www.student.montefiore.ulg.ac.be/~merciadri/
- -- 

If you fake it, you can't make it.
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