[pdftex] pdftex-pdfcrypt update
Heiko Oberdiek
oberdiek at ruf.uni-freiburg.de
Wed Mar 28 19:47:32 CEST 2001
At 17:08 28.03.2001 +0200, 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.
But AR does not know, what is encrypted, and what not, so
the files are displayed in a wrong way (I have tested \url with
hyperref and thumbpdf (no thumbnails are shown)).
If I understand the pdf spec. correctly, either nothing or
_all_ have to be encrypted.
Yours sincerely
Heiko <oberdiek at ruf.uni-freiburg.de>
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