Credential Wrapping: From Anonymous Password Authentication to Anonymous Biometric Authentication

The anonymous password authentication scheme proposed in ACSAC'10 under an unorthodox approach of password wrapped credentials advanced anonymous password authentication to be a practically ready primitive, and it is being standardized. In this paper, we improve on that scheme by proposing a new method of "public key suppression" for achieving server-designated credential verifiability, a core technicality in materializing the concept of password wrapped credential. Besides better performance, our new method simplifies the configuration of the authentication server, rendering the resulting scheme even more practical. Further, we extend the idea of password wrapped credential to biometric wrapped credential}, to achieve anonymous biometric authentication. As expected, biometric wrapped credentials help break the linear server-side computation barrier intrinsic in the standard setting of biometric authentication. Experimental results validate the feasibility of realizing efficient anonymous biometric authentication.