Privacy concernsThis product description will self-destruct

“He who controls the past, controls the future; he who controls the present, controls the past” — this is the motto of the Ministry of Information in George Orwell’s 1984. Little did Orwell know. Computers have made it virtually impossible to leave the past behind. College Facebook posts or pictures can resurface during a job interview. A lost cell phone can expose personal photos or text messages. A legal investigation can subpoena the entire contents of a home or work computer, uncovering incriminating, inconvenient or just embarrassing details from the past.

It is thus a good thing that the University of Washington has developed a way to make such information expire. After a set time period, electronic communications such as e-mail, Facebook posts, and chat messages would automatically self-destruct, becoming irretrievable from all Web sites, inboxes, outboxes, backup sites, and home computers. Not even the sender could retrieve them.

“If you care about privacy, the Internet today is a very scary place,” said Tadayoshi Kohno, a UW assistant professor of computer science. “If people understood the implications of where and how their e-mail is stored, they might be more careful or not use it as often.”

The team of UW computer scientists developed a prototype system called Vanish that can place a time limit on text uploaded to any Web service through a Web browser. After a set time text written using Vanish will, in essence, self-destruct. A paper about the project went public today and will be presented at the Usenix Security Symposium on 10-14 August in Montreal.

Co-authors on the paper are doctoral student Roxana Geambasu, Kohno, professor Hank Levy, and undergraduate student Amit Levy, all with the UW’s department of computer science and engineering. The research was funded by the National Science Foundation, the Alfred P. Sloan Foundation and Intel Corp.

“When you send out a sensitive e-mail to a few friends you have no idea where that e-mail is going to end up,” Geambasu said. “For instance, your friend could lose her laptop or cell phone, her data could be exposed by malware or a hacker, or a subpoena could require your e-mail service to reveal your messages. If you want to ensure that your message never gets out, how do you do that?”

Many people believe that pressing the “delete” button will make their data go away. “The reality is that many Web services archive data indefinitely, well after you’ve pressed