Efficient CCA-secure PKE from identity-based techniques

Abstract

Boneh, Canetti, Halevi, and Katz showed a general method for constructing CCA-secure public key encryption (PKE) from any selective-ID CPA-secure identity-based encryption (IBE) schemes. Their approach treated IBE as a black box. Subsequently, Boyen, Mei, and Waters demonstrated how to build a direct CCA-secure PKE scheme from the Waters IBE scheme, which is adaptive-ID CPA secure. They made direct use of the underlying IBE structure, and required no cryptographic primitive other than the IBE scheme itself. However, their scheme requires long public key and the security reduction is loose. In this paper, we propose an efficient PKE scheme employing identity-based techniques. Our scheme requires short public key and is proven CCA-secure in the standard model (without random oracles) with a tight security reduction, under the Decisional Bilinear Diffie-Hellman (DBDH) assumption. In addition, we show how to use our scheme to construct an efficient threshold public key encryption scheme and a public key encryption with non-interactive opening (PKENO) scheme. © 2010 Springer-Verlag.