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 $\mathcal {F}_{SAGCOM}$, $\mathcal {F}_{IDSC}$ and $\mathcal {F}_{GKD}$, respectively. Then, we construct a UC secure identity-based signcryption protocol $\pi_{IDSC}$. Moreover, we shows that the identity-based signcryption $\pi_{IDSC}$ securely realizes the ideal functionality $\mathcal {F}_{IDSC}$ if and only if the corresponding protocol IDSC is secure. Finally, based on the identity-based protocol, we propose a group communication scheme $\pi_{SAGCOM}$, which can securely realizes the ideal functionality $\mathcal {F}_{SAGCOM}$ in the $(\mathcal {F}_{IDSC},\mathcal {F}_{GKD})$-hybrid model