Want to make your e-mail disappear?

'VANISH' | Software in the works erases sensitive data from Internet after a specified time -- so it doesn't last forever

Now, there's a way the super-careful can make their sensitive electronic data -- e-mails, photos, Facebook posts and other information -- self-destruct in 8 to 32 hours.

You know, a little like the way the tapes with the super-secret instructions would do at the start of "Mission: Impossible," only without the hissing and the smoke.

The software, called Vanish, requires you to select each piece of data you want to disappear in advance. Sorry, it doesn't work on that e-mail you sent in haste and now wish you hadn't sent. And, no, it won't keep the recipient from printing out a copy.

"The goal of Vanish is to bring the natural human tendency to forget to an Internet whose nature is to remember forever," says Tadayoshi Kohno, an assistant professor of computer science and engineering at the University of Washington whose class developed a beta version of the software -- probably a bit complicated for most casual users but available now for free download at http://vanish.cs.washing ton.edu -- and is working to create a production-quality version.

"If I say something online today, I have no idea what someone will make of that information 5, 10 or 15 years from now," he said. "I'd like to make sure that that future doesn't have access to the information I send today."

Vanish works by using encryption techniques, Kohno says. The digital message is locked in a virtual box, with the key to the box broken into 100 pieces and distributed so it can't be put together again after a set amount of time.

Kohno's research is funded in part by a $450,000 National Science Foundation grant.

He says Vanish won't be available as a commercial or retail product for at least two years.

Still, if you want to really make sure no one else gets hold of sensitive information, it's tough for most people to cover all of their electronic tracks, says Alison Chung, president and founder of Teamwerks, a Chicago consulting firm specializing in re-creating activity from computers and computer servers.

"We can even track people texting," Chung says. "I tell my clients, 'If you're concerned about what is going to be shown, don't do it.' ... Encryption does, to some extent, hinder people from finding things. But there are many other ways of finding information."