More efficient CCA-secure unidirectional proxy re-encryption schemes without random oracles


Zhenfu Cao, Department of Computer Science and Engineering, Shanghai Jiao Tong University, No. 800, Dongchuan Road, Shanghai, 200240, China.



In this paper, we present a more efficient chosen-ciphertext secure proxy re-encryption scheme in the standard model with less ciphertext size and without any strong unforgeable one-time signature. Our scheme is unidirectional and single-hop. The security of our scheme is under the reasonable complexity assumption—the decisional bilinear Diffie–Hellman assumption in bilinear groups. There are no proxy re-encryption schemes achieving chosen-ciphertext security in the standard model without a strong unforgeable one-time signature in the literature. Copyright © 2012 John Wiley & Sons, Ltd.