Paper 2007/254
Fully Secure Proxy Re-Encryption without Random Oracles
Jun Shao, Zhenfu Cao, Licheng Wang, and Xiaohui Liang
Abstract
In a proxy re-encryption scheme, a semi-trusted proxy, with some additional information, can transform a ciphertext under Alice's public key into a new ciphertext under Bob's public key on the same message, but cannot learn any information about the messages encrypted under the public key of either Alice or Bob. In this paper, we propose two new unidirectional proxy re-encryption schemes, where a proxy can transform a ciphertext for Alice into a new ciphertext for Bob, but not vice versa. Note that, unidirectional proxy re-encryption is more powerful than bidirectional one, since a bidirectional scheme can always be implemented by an unidirectional one. Furthermore, these two schemes can be proved \emph{in the standard model}, chosen-ciphertext secure based on Decisional Bilinear Inverse Diffie-Hellman assumption and master key secure based on Extended Discrete Logarithm assumption. To our best knowledge, our proposals are the first fully secure (CCA-secure and master key secure) proxy re-encryption schemes in the standard model.
Note: Some typos are corrected. And delete the proof of the 1st scheme, and add a proof for the 3rd scheme.
Metadata
- Available format(s)
- -- withdrawn --
- Category
- Public-key cryptography
- Publication info
- Published elsewhere. Unknown where it was published
- Keywords
- proxy re-encryption
- Contact author(s)
- chn junshao @ gmail com
- History
- 2007-10-29: withdrawn
- 2007-06-27: received
- See all versions
- Short URL
- https://ia.cr/2007/254
- License
-
CC BY