Threshold Password-Based Authentication Using Bilinear Pairings

We present a new threshold password-based authentication protocol that allows a roaming user(a user who accesses a network from different client terminals) to download a private key from remote servers with knowledge of only his identity and password. He does not need to carry the smart card storing his private information. We aim that a protocol has to allow a user to get his private key from the servers, even if some of the servers are compromised under the multi-server roaming system. In this paper, we firstly suggest a threshold password-only roaming protocol using (k,n)-threshold scheme which only k honest servers or more are engaged to reconstruct a secret key. Our scheme is based on bilinear pairings which could be built from Weil pairing or Tate pairing.