An Efficient and Provably Secure IBE Scheme with Short System Parameters

In this paper we build a new identity-based encryption scheme, which has short system parameters and is provably secure in the random oracle model. Comparing with the identity-based encryption scheme proposed by gentry, we all has short system parameters, but in contrast the security of our identity-based encryption scheme based on a stronger and commonly used assumption, namely bilinear decision Diffie-HelIman assumption. So informally, our identity-based encryption scheme is more secure. At last, by comparing the degree of reduction with the identity-based encryption scheme proposed by Boneh and Franklin, we can show that our scheme is efficient too.