To protect your privacy, hand over your data

Personal control
If people gain control of their own personal data mines, rather than allowing them to be built and held by corporations, they could use them not only to prove who they are but also to inform smart recommendation systems, Pent land says.

He recognizes that allowing even limited access to detailed logs of your actions may seem scary. But he argues it is safer than relying on key-like codes and numbers, which are vulnerable to theft or forgery.

"It is not feasible for a single organization to own all this rich identity information," Pent land says. What he envisages instead is the creation of a central body, supported by a combination of cell phone networks, banks and government bodies.

That bank could provide "slices" of data to third parties that want to check a person's identity. That information could be much like that required to verify high-level security clearance in government, says pent land.