On the Security of Homomorphic Encryption Schemes with Restricted Decryption Oracles  

作　　者：MA Guangsheng LI Hongbo 

机构地区：[1]School of Mathematics and Physics,North China Electric Power University,Beijing 100096,China [2]Academy of Mathematics and Systems Science,Chinese Academy of Sciences,Beijing 100190,China [3]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Systems Science & Complexity》2024年第5期2240-2261,共22页系统科学与复杂性学报（英文版）

基　　金：partially supported by China National Key Research and Development Projects under Grant Nos.2020YFA0712300 and 2018YFA0704705。

摘　　要：Fully homomorphic encryption(FHE)can be used for privacy-preserving aggregation of medical data.In this typical application,the security against passive attacks has been well studied by Li and Micciancio(2021).In this paper,the authors further consider a“nearly passive”kind of attack,where the attacker may behave like a passive attacker in the view of the third-party server.To capture the security against this hard-to-detect attack,the authors propose a new notion of IND-CPA^(rD)security.The authors show that the standard LWE encryption and its related FHE schemes can not defend against IND-CPA^(rD)attack,even under a stricter rule limiting the content and number of queries made by the attacker.To make the application of FHE schemes more secure,the authors discuss some possible modifications that may serve as countermeasures to IND-CPA^(rD)attack.

关 键 词：Homomorphic encryption PRIVACY secure cloud computing SECURITY 

分 类 号：TP309.7[自动化与计算机技术—计算机系统结构]