Title
Improved anonymous proxy re-encryption with CCA security
Abstract
Outsourcing private data and heavy computation tasks to the cloud may lead to privacy breach as attackers (e.g., malicious outsiders or cloud administrators) may correlate any relevant information to penetrate information of their interests. Therefore, how to preserve cloud users' privacy has been a top concern when adopting cloud solutions. In this paper, we investigate the identity privacy problem for the proxy re-encryption, which allows any third party (e.g., cloud) to re-encrypt ciphertexts in order to delegate the decryption right from one to another user. The relevant identity information, e.g., whose ciphertext was re-encrypted to the ciphertext under whose public key, may leak because re-encryption keys and ciphertexts (before and after re-encryption) are known to the third party. We review prior anonymity (identity privacy) notions, and find that these notions are either impractical or too weak. To address this problem thoroughly, we rigorously define the anonymity notion that not only embraces the prior anonymity notions but also captures the necessary anonymity requirement for practical applications. In addition, we propose a new and efficient proxy re-encryption scheme. The scheme satisfies the proposed anonymity notion under the Squared Decisional Bilinear Diffie-Hellman assumption and achieves security against chosen ciphertext attack under the Decisional Bilinear Diffie-Hellman assumption in the random oracle model. To the best of our knowledge, it is the first proxy re-encryption scheme attaining both chosen-ciphertext security and anonymity simultaneously. We implement a prototype based on the proposed proxy re-encryption scheme and the performance study shows that it is efficient.
Year
DOI
Venue
2014
10.1145/2590296.2590322
ASIACCS
Keywords
Field
DocType
anonymity,distributed systems,proxy re-encryption,outsourced computation,public key cryptosystems,chosen-ciphertext security
Internet privacy,Computer security,Computer science,Delegate,Random oracle,Chosen-ciphertext attack,Ciphertext,Anonymity,Public-key cryptography,Cloud computing,Proxy re-encryption
Conference
Citations 
PageRank 
References 
2
0.39
22
Authors
4
Name
Order
Citations
PageRank
Qingji Zheng120.39
Wei Zhu220.39
Jiafeng Zhu321.07
Xinwen Zhang469746.90