Research: 'Delete' really means delete

SEATTLE, July 22 (UPI) -- Deleting those incriminating or embarrassing online posts and photos could become permanent, thanks to a prototype program developed at a U.S. university.

The University of Washington has come up with a way to make that pesky information -- that seemingly surfaces at inopportune times -- self-destruct after a specified period of time, becoming irretrievable from all Web sites, in- and outboxes, backup sites and computers, the university said in a release.

"If you care about privacy, the Internet today is a very scary place," UW computer scientist Tadayoshi Kohno said. "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."

University computer scientists developed a prototype system called "Vanish" that can place a time limit on text uploaded to any Web service through a browser. Once the time period expires, the text written using Vanish will, well, vanish.

The Vanish prototype erases data using the natural turnover on large file-sharing systems, the team said. For each message it sends, Vanish creates a secret key and then encrypts the message with that key. It then breaks the key into dozens of pieces, scattering the pieces randomly on computers belonging to worldwide file-sharing networks. Because the file-sharing system constantly changes as computers join or leave the network, parts of the key become permanently inaccessible over time. Once enough key parts are lost, the original message can no longer be deciphered.