[pdftex] pdftex-pdfcrypt update
Ricardo Sanchez Carmenes
carmenes at bioquimica.uniovi.es
Thu Mar 29 03:30:31 CEST 2001
On Wed, 28 Mar 2001, Hans Hagen wrote:
> At 05:22 PM 3/28/01 +0100, Heiko Oberdiek wrote:
>
> ...
>
> >But it is a hard job to do it in pdfTeX, because pdfTeX
> >provides low level features, where pdf code is directly
> >inserted. So _all_ insertions (by \pdfobj, \pdfstartlink, ...)
> >have to be scanned to detect strings and streams in order
> >to encrypt them.
> >
> >For example two test files, that are currently not encrypted
> >in a correct way:
>
> ...
>
> it may be enough to encrypt compressed streams only (i.e. text and
> graphical data), since encripting any dict or descriptive object is a
> slowdown and not that useful.
That's right. This is how the encryption standard is defined.
The PDFref specs are clear.
Ricardo.
More information about the pdftex
mailing list