Is it possible to e-mail word, excel or powerpoint files that self-destruct after a set expiry time. Our business uses NDA agreements to manage confidentiality but we feel uncomfortable e-mailing Office documents that contain valuable corporate information. It would be reassuring if we knew they would automatically delete themselves after 3 months.
http://www.youtube.com/watch?v=dWfLThXoC8Y sorry couldn't resist.
I've looked into this when I was working for a law firm setting up secure virtual datarooms for M&A transactions. There are a few things you can do with DRM, but it generally gets very complicated. I looked into applying DRM to documents, and various solutions for tracking access, preventing printing and securing the website to stop documents being downloaded in full etc. Office has DRM capabilities (which they call IRM).
In the end you have to go back to basics and ask yourself "what risk am I trying to avoid?" Basically you need to let people see the information, but prevent them from passing it on to someone else. But however technologically sophisticated your solution to the problem, one thing always gets in the way. It's called human nature.
Sure, you can spend money on products which will stop you emailing a document, prevent printing, expire it after a certain time etc etc. But it's not the document you want to protect. It's the information contained in the document. Once someone has seen the document, the information is partly out of your control. If someone wants to take the risk of disclosure, they will. Nothing can stop them telling someone else what they have seen. OK, they may not be able to get the whole document word for word, but most likely enough to do whatever damage you are trying to prevent. Private investigators and spies would be out of a job otherwise.
Bottom line is, your non-disclosure agreement and litigation in the event of disclosure are your only true protection. For my projects, the "best efforts" solution I put in place was to allow access only via the secure website, and not give direct access to the word/excel etc, but to convert them on the fly to secured, non-printable PDFs which were watermarked with the name of the recipient and timestamped. So if a copy appeared somewhere it shouldn't, we had a chance of tracking it back to the guilty party. After that it's over to the lawyers...