251 words on Mac OS X
I haven’t really used any encrypted PDF file so far, but PDF encryption is a feature of Mac OS X.4 that I ran into recently. You can create encrypted PDF files by using Preview’s Save capabilities or, possibly more conveniently, the ‘Encrypt PDF’ Automator action, a workflow with which should be available as a PDF Service on the computer and let you turn anything you can print into an encrypted PDF.
The more crucial part in this topic may be played by the ability to open and display encrypted PDF files which is available in X.4 as well. I can’t judge its technical capabilities apart from saying that it managed to open the few encrypted files I got my hands on. But I have to say that I quite like the UI Apple use for this.
It is simple and catches your attention. And it’s probably a good place to ignore the guidelines suggesting to open a sheet for password entry. It’s good to open the full window – rather than a preliminary password dialogue, say – right away. And it’s good to not clutter the screen with yet another window if you have all the space of the existing window to use for password entry. Very efficient and nice.
The only thing that confused me a little is that I got scroll bars in the little window you see above. That suggests that (at least) the document’s size isn’t stored in an encrypted way. Which I consider to be odd.