WCSE

Faster Binary Arithmetic Operations on Encrypted Integers

Abstract— Fully homomorphic encryption (FHE) makes a large number of applications available in cloud computing environment. Following Gentry’s seminal work, many FHE schemes have been presented. Among known FHE schemes, the Brakerski-Gentry-Vaikuntanathan scheme with corresponding optimizations is one of the most potential candidates for practical use, and has been implemented by Shoup and Halevi in a homomorphic encryption C++ library HElib. Based on HElib, Xu et al. (2016) reported their implementation of binary arithmetic operations over encrypted integers. In this paper, we optimize their implementation further. More specifically, the multi-thread technique is used to accelerate the arithmetic circuits. Moreover, ciphertext slots are fully used in our implementation. As a result, these techniques enable us to evaluate 600 additions of two 64-bit integers simultaneously within 25 seconds, about 0.042 seconds for per-addition time on average.

Index Terms— FHE, HElib, integer arithmetic

Jingwei Chen, Yong Feng, Wenyuan Wu
Chongqing Key Laboratory of Automated Reasoning and Cognition, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, CHINA
Yang Liu
College of Information Science and Engineering, Chongqing Jiaotong University, CHINA

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Cite: Jingwei Chen, Yong Feng, Yang Liu, Wenyuan Wu, "Faster Binary Arithmetic Operations on Encrypted Integers," Proceedings of 2017 the 7th International Workshop on Computer Science and Engineering, pp. 956-960, Beijing, 25-27 June, 2017.