IK-CPA security implies IE-CCA security in the random oracle model  

作　　者：XUE Rui 

机构地区：[1]State Key Laboratory of Information Security,Institute of Software,Chinese Academy of Sciences

出　　处：《Science China(Information Sciences)》2013年第3期175-185,共11页中国科学（信息科学）（英文版）

基　　金：supported by the Fund of the China Scholarship Council,National Natural Science Foundation of China(Grants Nos.60873260,60903210);National High Technology Research and Development Program of China(Grant No.2009AA01Z414);National Basic Research Program of China(Grant No. 2007CB311202)

摘　　要：Key-privacy is a notion of security that is concerned with the key anonymity in public-key en- cryption. Some popular schemes keep key-privacy, while others do not. Key-privacy has been shown to be orthogonal to data-privacy within one cryptosystem. This paper investigates the relationship between key- privacy and data-privacy in public-key encryption. We show that the existence of IK-CPA secure cryptosystems implies the existence of IE-CCA secure cryptosystems in the random oracle Inodel. The main contributions include a novel construction of a family of injective one-way trapdoor functions directly based on any IK-CPA secure public-key cryptosystem in the random oracle model. This construction adopts a novel idea in the con- struction compared to the existing one. The latter was based on unapproximable trapdoor predicates. The novelty of the construction allows to show that the injective trapdoor functions are secure under correlated products with respect to uniform repetitional distribution. That further allows us to conclude, in the random oracle model, that the existence of IK-CPA secure public-key cryptosystems implies the existence of CCA secure cryptosystems by a result of Rosen and Segev.Key-privacy is a notion of security that is concerned with the key anonymity in public-key en- cryption. Some popular schemes keep key-privacy, while others do not. Key-privacy has been shown to be orthogonal to data-privacy within one cryptosystem. This paper investigates the relationship between key- privacy and data-privacy in public-key encryption. We show that the existence of IK-CPA secure cryptosystems implies the existence of IE-CCA secure cryptosystems in the random oracle Inodel. The main contributions include a novel construction of a family of injective one-way trapdoor functions directly based on any IK-CPA secure public-key cryptosystem in the random oracle model. This construction adopts a novel idea in the con- struction compared to the existing one. The latter was based on unapproximable trapdoor predicates. The novelty of the construction allows to show that the injective trapdoor functions are secure under correlated products with respect to uniform repetitional distribution. That further allows us to conclude, in the random oracle model, that the existence of IK-CPA secure public-key cryptosystems implies the existence of CCA secure cryptosystems by a result of Rosen and Segev.

关 键 词：injective trapdoor functions IK-CPA security random oracle model IE-CCA security 

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