Universally Composable Secure Group Communication

This paper analyzes group communication within the universally composable framework. We first propose the group communication model, identity-based signcrytion model and group key distribution model in the UC framework by designing the ideal functionality FSAGCOM , FIDSC and FGKD, respectively. Then, we construct a UC secure identity-based signcryption protocol πIDSC . Moreover, we shows that the identity-based signcryption πIDSC securely realizes the ideal functionality FIDSC if and only if the corresponding protocol IDSC is secure. Finally, based on the identity-based protocol, we propose a group communication scheme πSAGCOM , which can securely realizes the ideal functionality FSAGCOM in the (FIDSC ,FGKD)-hybrid model.