Just as individual identity is fundamental to our face-to-face interactions, digital identity is fundamental to our interactions in the online world. Unfortunately, many of the challenges associated with the Internet stem from the lack of widely deployed, easily understood, and secure identity solutions. This should come as no surprise. After all, the Internet was designed for sharing information, not for securely identifying users and protecting personal data. However, the rapid proliferation of online theft and deception and the widespread misuse of personal information are threatening to erode public trust in the Internet and thus limit its growth and potential.