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?
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Merciadri Luca wrote:
> Johannes Wiedersich wrote:
>> Why would an
>> honest soul ever allow information to be read, but not printed?
>>
> To maintain honesty? An honest soul (i.e. me, here) has to send some
> data to some dishonest person.
The problem is: either you give data to some dishonest person or you
don't give that data to some dishonest person. Tertium non datur.
>> Even with acroread it is possible to print screenshots of the documents.
>> Might be a pain to reconstruct a multipage document, but not impossible.
>>
> I know, and we all know this. But this needs some determination, because
> it needs some time. And when such problems arise, one often thinks (or
> should, at least, think) `Do I really need to copy this using that
> painful way, to bypass some limitation which is actually imposed to me
> by an honest person?' This is another aspect of security. There are the
> technical means, and all the infringements which can be done. But,
> sometimes, `le jeu n'en vaut pas la chandelle.'
FWIW, if you'd like to rely on such a scheme for security by obstacles,
you'd have to use something else than pdf. pdf's scheme is broken.
That's all.
The reason that it is broken for pdfs is that the specifications for pdf
are freely available, and thus alternative pdf readers have been
developed. Your scheme would require closed specifications and closed
software to work. This list, however, is all about free software.
- --
Johannes
In questions of science, the authority of a thousand is not worth the
humble reasoning of a single individual.
- - Galileo Galilei, physicist and astronomer (1564-1642)
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Reply to:
- References:
- 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?
- From: Merciadri Luca <Luca.Merciadri@student.ulg.ac.be>
- 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?
- From: Merciadri Luca <Luca.Merciadri@student.ulg.ac.be>
- 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?
- From: Sjoerd Hardeman <sjoerd@lorentz.leidenuniv.nl>
- 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?
- From: Merciadri Luca <Luca.Merciadri@student.ulg.ac.be>
- 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?
- From: Mikhail Gusarov <dottedmag@dottedmag.net>
- 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?
- From: Merciadri Luca <Luca.Merciadri@student.ulg.ac.be>
- 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?
- From: Johannes Wiedersich <johannes@physik.blm.tu-muenchen.de>
- 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?
- From: Merciadri Luca <Luca.Merciadri@student.ulg.ac.be>