Universally Composable Identity-Based Encryption
Ryo Nishimaki, Y. MANABE, T. OKAMOTO · IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences · 2008
Identity-based encryption (IBE) is one of the most important primitives in cryptography, and various security notions of IBE (e. g., IND-ID-CCA2, NM-ID-CCA2, IND-sID-CPA etc.) have been introduced. The relations among them have been clarified recently. This paper, for the first time, investigates the security of IBE in the universally composable (UC) framework. This paper first defines the UC-security of IBE, i. e., we define the ideal functionality of IBE, FIBE. We then show that UC-secure IBE is equivalent to conventionally-secure (IND-ID-CCA2-secure) IBE.