Two-Server Password-Authenticated Secret Sharing UC-Secure Against Transient Corruptions

Protecting user data entails providing authenticated users access to their data. The most prevalent and probably also the most feasible approach to the latter is by username and password. With password breaches through server compromise now reaching billions of affected passwords, distributing the password files and user data over multiple servers is not just a good idea, it is a dearly needed solution to a topical problem. Threshold password-authenticated secret sharing (TPASS) protocols enable users to share secret data among a set of servers so that they can later recover that data using a single password. No coalition of servers up to a certain threshold can learn anything about the data or perform an offline dictionary attack on the password. Several TPASS protocols have appeared in the literature and one is even available commercially. Although designed to tolerate server corruptions, unfortunately none of these protocols provide details, let alone security proofs, about how to...

• Type: Journal
• Year: 2015
• Where: PKC
• Authors: Jan Camenisch, Robert R. Enderlein, Gregory Neven
• Keywords: Cryptology, PKC 2015