[pdftex] Enabling Security in PDF

Paul Vojta vojta at Math.Berkeley.EDU
Sun Nov 23 00:13:55 CET 2003

On 2003-11-21 10:05:07 +0100, Martin Schröder wrote:
> On 2003-11-21 10:46:08 +0200, David Vannucci wrote:
> > Is it possible to enable PDF document security in the hyperref hypersetup or
> > some other place? Setting options such as user password, master password,
> > encryption level, changing, printing.
> Not anymore. Is it possible for you to read http://www.pdftex.org/NEWS ?
> Best regards
>         Martin

One of the difficulties with posting on mailing lists (and with written
communication in general) is that it omits other forms of communication,
such as voice inflection, which often convey the tone in which the response
intends.  For example, "Thanks a lot" can be a genuine thank-you, or
(when spoken with sarcastic intonation) can mean quite the opposite.
I too have been caught by this in the past.

Unfortunately, the above response comes across as sarcastic, as if the
person asking the question was stupid not to have checked the NEWS file.
If the response was so intended, then it was inappropriate.

As I read the original question, this is a new user of pdftex, and as
such has no reason to look at the NEWS file.  Note that the pdftex manual
makes no reference to the NEWS file, and the README file says, "See the
file NEWS for changes to the program."  Since a new user would not be
familiar with old versions of the program, they have no reason to look
at that file.  After all, when we teach history to children, we give
them a textbook, not a stack of old newspapers.

(And also, if the original poster had instead asked something like "I
seem to recall that pdftex had encryption capabilities, but now I can't
find them...", then perhaps they could have been expected to have read
NEWS, but IMHO a more straightforward reply would have been more appropriate,
such as:  "That feature has been removed:  see http://www.pdftex.org/NEWS
for details.")

I would also like to add (and this part is addressed to the maintainers(s)
of pdftex, not to M.S.) that the pdftex manual is potentially unclear on
the issue of encryption:  it says,

	The cover of this manual shows a simple PDF file. Unless
	compression and/or encryption is applied, ...

which suggests that encryption is possible with pdftex.

This is not the first time that removal of features has caused confusion
about pdftex.  Perhaps a section on "removed features" could be added to
the manual, listing those features that have been removed, and the underlying
reasons for doing so.

(Incidentally, the pdftex manual *still* claims that tiff files are
supported for graphics inclusion.)

The above references to the manual refer to the versions available on
the web at <ULR:http://www.tug.org/applications/pdftex/>.  These are
dated 21 November 2000 (except for the letter-sized pdf, which was updated
on 1 March 2001).

I think it *is* reasonable for users to expect the documentation provided
with pdftex to be correct and up to date.  As the maintainer of (non-k) xdvi,
I feel that I speak with some authority when I say that keeping the
documentation up to date (especially when *removing* features) is not
a big burden, and should be viewed as an integral part of the software
development process.


Paul Vojta
vojta at math.berkeley.edu

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