Conditional Proxy Re-Encryption Secure against Chosen-Ciphertext Attacks
Conference Proceeding Article
In a proxy re-encryption (PRE) system , a proxy, authorized by Alice, can convert a ciphertext for Alice into a ciphertext for Bob without seeing the underlying plaintext. PRE has found many practical applications requiring delegation. However, it is inadequate to handle scenarios where a fine-grained delegation is demanded. To overcome the limitation of existing PRE systems, we introduce the notion of conditional proxy re-encryption (C-PRE), whereby only ci-phertext satisfying a specific condition set by Alice can be transformed by the proxy and then decrypted by Bob. We formalize its security model and propose an efficient C-PRE scheme, whose chosen-ciphertext security is proven under the 3-quotient bilinear Diffie-Hellman assumption. We further extend the construction to allow multiple conditions with a slightly higher overhead.
Information Security and Trust
Proceedings of the 4th International Symposium on Information, Computer, and Communications Security (ASIACCS '09), Sydney, Australia, March 10-12
City or Country
Weng, Jian; DENG, Robert H.; DING, Xuhua; CHU, Cheng-Kang; and LAI, Junzuo.
Conditional Proxy Re-Encryption Secure against Chosen-Ciphertext Attacks. (2009). Proceedings of the 4th International Symposium on Information, Computer, and Communications Security (ASIACCS '09), Sydney, Australia, March 10-12. 322-332. Research Collection School Of Information Systems.
Available at: http://ink.library.smu.edu.sg/sis_research/453