What is "u-prove"

U-Prove is a digital credential technology for claims-based identity management invented by Stefan Brands and developed by Credentica. It simultaneously provides for strong security, scalability, and privacy (including anonymity), and allows for claims to be efficiently tied to the use of smart cards. In 2008, Microsoft acquired the technology, including all of the underlying patents, with the stated goal of opening it up.

In March 2010, Microsoft announced the release of a cryptographic specification and open source API implementation code for part of the U-Prove technologies as a Community Technology Preview under Microsoft's Open Specification Promise.