Secret handshakes with dynamic expressive matching policy

Abstract

Secret handshake is an important building block of private communication over public networks, which allows two members of the same group to secretly authenticate each other and agree on a shared key for further communication. Ateniese et al. [1] introduced attribute based secret handshake, in which a group member Alice can complete the handshake protocol with another group member Bob by specifying the attributes Bob must have. In this paper, we propose the first efficient attribute-based secret handshake scheme which supports arbitrary matching policies with unlinkable and reusable credentials. Specifically, we first present a generic construction of attribute-based secret handshakes from centralized ciphertext-policy attribute-based encryption (CP-ABE). Based on the construction, we present a highly efficient attribute-based secret handshake scheme employing the CP-ABE scheme in [18].