CCA2 Secure IBE: Standard Model Efficiency through Authenticated Symmetric Encryption.
Eike Kiltz, Yevgeniy Vahlis · 2008
We propose two constructions of chosen-ciphertext secure identity-based encryption (IBE) schemes. Our schemes have a security proof in the standard model, yet they offer performance competitive with all known random-oracle based schemes. The efficiency improvement is obtained by combining modifications of the IBE schemes by Waters [41] and Gentry [23] with authenticated symmetric encryption.