A UC-Secure Authenticated Contributory Group Key Exchange Protocol Based on Discrete Logarithm

摘要

Authenticated key exchange protocols allow parties to establish a common session key which in turn is fundamental to building secure channels. Authenticated group key exchange protocols allow parties to interact with each other and establish a common group session key and avoid peer to peer key exchange; in other words they pave the way to build a broadcast channel. We construct an authenticated group key exchange protocol over UC framework which has the contributiveness property; i.e., the output is not biased by inputs of any party. Our protocol uses CRS model and discrete logarithm. Other protocols over UC framework either are denned over RO model or benefit from a non-standard hardness assumption.