“Roxana Geambasu is a computer science graduate student at the University of Washington in Seattle, where she’s been working on self-destructing data. The simplest application is a form of e-mail that comes with a finite life span.
“‘After the time out, you will never be able to read the message again,’ she says.
“The system is called Vanish, and it works by encrypting your data — e-mails, photos, Facebook posts — then placing the decryption ‘keys’ in several places around the Internet. The keys are readily available to anyone for a few hours. But as the keys disappear, the message rots away. All copies become unreadable; even the copies made along the way — at the Internet service provider, at the National Security Agency, wherever.”