Adaptive security in identity-based authenticated key agreement with multiple private key generators

Abstract

We define a security model to capture some adaptive security for identity-based authenticated key agreement with multiple private key generators (PKGs). Previous researches assume that a party is statically bound to its PKG. In our model, an adversary can adaptively control the binding between a party and a PKG, and moreover, the adversary is allowed to obtain private keys from different PKGs on the same identity. Based on this model, we propose an adaptively secure protocol under the gap Diffie-Hellman assumption in the random oracle model.