[greenstone-users] RE: how to restrict documents

From Gordon Paynter
DateMon, 21 Apr 2003 09:05:05 -0700 (PDT)
Subject [greenstone-users] RE: how to restrict documents
Hi Deepak, Will:

The Greenstone Users mailing list address recently changed, and I notice
you're using the old address. The new address is
greenstone-users@orc.cs.waikato.ac.nz. Posting to that list might get you
a few more responses.

As Will suggests, Deepak, your best option might be to rely on the
security built into PDF, then only serve up PDF documents to the user, not
Greenstone's HTML equivalent's of the PDF documents.


> G'day Deepak,
>>in the course of building collection of PDF and word documents i feel
>> need of some technique to restict the user [reader] to print the PDF
>> documents or to restict to download of the documents. I
>>want to give the read access of PDF documents to the
>>readers[users] rather than downloading it.
> As far as I am aware it is impossible to stop users downloading what
> they can see in their browser without using a specialised Java applet.
> I'm not so sure about Word documents, but I can help a little with
> PDFs...
> You can encrypt your PDFs in a way which allows the user (who doesn't
> have the password) to view and save the document, but not to copy from
> or print the document. The saved document cannot be copied or printed
> either. A number of free (and $$$) pdf utilities allow you to do this. I
> can't remember which utility I use, but I'll mail a follow up when I do
> remember.
> There is another (not so nice but more secure) option. PHParchitect
> magazine had a free downloadable article in January about building a
> "Web-based PDF Viewer". It basically creates images of the PDF page the
> user wants to view on the fly. The user doesn't access the PDF directly.
> The good news is that hardly anyone will want to copy then OCR a pile
> of images - the bad news is that this will use up your bandwidth and
> server resources if you have many users browsing PDFs at the same time.
> The link is: http://www.phparch.com/issuedata/2003/jan/sample.php
> Hope this helps,
> Will.