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Conditional proxy re-encryption - A more efficient construction
Date Issued
21-07-2011
Author(s)
Vivek, S. Sree
Sharmila Deva Selvi, S.
Radhakishan, V.
Pandu Rangan, C.
Abstract
In a proxy re-encryption (PRE) scheme, Alice gives a special information to a proxy that allows it to transform messages encrypted under Alice's public key into a encryption under Bob's public key such that the message is not revealed to the proxy. In [14], Jian Weng and others introduced the notion of conditional proxy re-encryption (C-PRE) and proposed a system using bilinear pairings. Later, a break for the same was published in [17] and a new C-PRE scheme with bilinear pairings was introduced. In C-PRE, the proxy also needs to have the right condition key to transform the ciphertext (associated with a condition set by Alice) under Alice's public key into ciphertext under Bob's public key, so that Bob can decrypt it. In this paper, we propose an efficient C-PRE scheme which uses substantially less number of bilinear pairings when compared to the existing one [17]. We then prove its chosen-ciphertext security under modified Computational Diffie-Hellman (mCDH) and modified Computational Bilinear Diffie-Hellman (mCBDH) assumptions in the random oracle model. © 2011 Springer-Verlag.
Volume
196 CCIS