General ⇒ Attempt at catching plagiarists

[_Joe_]

Hello all,
This is a cross-post with http://answers.yahoo.com/my-activity;_y ... ns-answers

I'm a teaching assistant at an engineering school. I have found an alarming number of plagiarists among one of the classes that I teach. Whenever I give them a tutorial on something and ask for a report about it later, many people just copy and paste from the tutorial slides I provided.
Now I produce all my documents using pdflatex and I was wondering if there's a way to provide alternative text to be copied to the clipboard when students try copy/pasting from a document.
I know I can prevent copying altogether by encrypting the PDF but this can be circumvented. Another approach I found is to use the accsupp package. I tried the following:

Code: Select all

\documentclass{article}
\usepackage{accsupp}
\usepackage{blindtext}
\begin{document}
\BeginAccSupp{ActualText={Stop Copying Other people's work!}}
\Blindtext[2][3]
\EndAccSupp
\end{document}

This works fine for the first page only. The rest of the document can easily be copied. Is there a way to make accsupp work for the whole document? Better yet, is there a package specifically suited for my purpose?
Any help would be really appreciated. Thanks

[Stefan Kottwitz]

Hi Joe,

as far as I know accsupp just works on the current page.

You could have a look at these free tools, I read about them in the pdfcrypt package documentation:

• pdftk
• Multivalent
• PDFBox
• PDFTrans

pdfcrypt itself is not supported for newer pdfTeX versions.

Stefan

[_Joe_]

Hello Stefan,
Thanks for the reply.
I already went through this. I looked at pdfcrypt, which lead me to pdftk.
pdftk is a wonderful tool in its own right. I used it to successfully prevent copying altogether. The problem is, PDF viewers that have the ability to sidestep DRM rules (like Okular), disregard the encryption completely. This is why I was looking for another approach.