An Improved Ciphertext Retrieval Scheme Based on Fully Homomorphic Encryption
LI Xinyan1, MOU Huajian2†, LU Dianjun31. School of Mathematics and Statistics, Yangtze Normal University, Chongqing 408100, China; 2. College of Computer Engineering, Yangtze Normal University, Chongqing 408100, China; 3. School of Mathematics and Statistics, Qinghai Normal University, Xining 810000, Qinghai, China
In order to guarantee the user’s privacy and the integrity of data when retrieving ciphertext in an untrusted cloud environment, an improved ciphertext retrieval scheme was proposed based on full homomorphic encryption. This scheme can encrypt two bits one time and improve the efficiency of retrieval. Moreover, it has small key space and reduces the storage space. Meanwhile, the homomorphic property of this scheme was proved in detail. The experimental results and comparisons show that the proposed scheme is characterized by increased security, high efficiency and low cost.
Key words:fully homomorphic encryption; public key size; the greatest common divisor (GCD) problem; ciphertext retrieval
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