A general compiler for password-authenticated group key exchange protocol in the standard model

Password-authenticated group key exchange (PGKE) protocols are critical for ensuring secure group communications for mobile devices. Until now, only few PGKE protocols have been proposed. However, literature about group key exchange (GKE) protocols consists of many research proposals in last few years. In this paper, we present a protocol compiler based on smooth projective hash functions. The proposed compiler can transform any GKE protocol into a secure PGKE protocol by adding 2 rounds of communication. We conduct the security of our compiler in the standard model without using various other assumptions. Our compiler is round-efficient in the sense that a constant-round PGKE can be derived from the proposal if the underlying protocol is a constant-round GKE protocol.