Provably secure cross-realm client-to-client password-authenticated key exchange protocol

Abstract

The cross-realm client-to-client password-authenticated key exchange protocol, which was proposed by Byun et al. in 2002, allows two clients in different realms with different passwords to agree on a common session key through their corresponding servers. From then on, many research works have been done. In this paper, we define a new formal security model of cross-realm C2C-PAKE which captures more desirable security requirements than the previous models. Then, we construct a new cross-realm C2C-PAKE key exchange protocol based on quadratic residues and prove its security in the model. In addition, both the communication complexity and the computational complexity are reduced in our protocol. © 2012 Springer Science+Business Media B.V.