%0 Journal Article
%T Efficient Conditional Proxy Re-Encryption With Chosen Cipher Text Security
%A S. Sree Vivek
%A S. Sharmila Deva Selvi
%A V. Radhakishan
%A C. Pandu Rangan
%J International Journal of Network Security & Its Applications
%D 2012
%I Academy & Industry Research Collaboration Center (AIRCC)
%X 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) with 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.
%K Random Oracle Model
%K Proxy Re-Cryptography
%K Conditional Proxy Re-encryption
%K Chosen Ciphertext Security.
%U http://airccse.org/journal/nsa/0312nsa14.pdf