CAJ | 학술논문

全同态加密在云计算等领域具有重要的应用价值,然而,现有全同态加密体制普遍存在公钥尺寸较大的缺陷,严重影响密钥管理与身份认证的效率.为解决这一问题,该文将无证书公钥加密的思想与全同态加密体制相结合,提出一种基于容错学习(LWE)问题的无证书全同态加密体制,利用前像可采样陷门单向函数建立用户身份信息与公钥之间的联系,无须使用公钥证书进行身份认证;用户私钥由用户自行选定,不存在密钥托管问题.体制的安全性在随机喻示模型下归约到判定性LWE问题难解性,并包含严格的可证安全证明.
전동태가밀재운계산등영역구유중요적응용개치,연이,현유전동태가밀체제보편존재공약척촌교대적결함,엄중영향밀약관리여신빈인증적효솔.위해결저일문제,해문장무증서공약가밀적사상여전동태가밀체제상결합,제출일충기우용착학습(LWE)문제적무증서전동태가밀체제,이용전상가채양함문단향함수건립용호신빈신식여공약지간적련계,무수사용공약증서진행신빈인증;용호사약유용호자행선정,불존재밀약탁관문제.체제적안전성재수궤유시모형하귀약도판정성LWE문제난해성,병포함엄격적가증안전증명.
@@@@Fully homomorphic encryption has important application in cloud computing. However, the existing fully homomorphic encryption schemes share a common flaw that they all use public keys of large scales. And this flaw may cause inefficiency of these schemes in the key and identity management. To solve this problem, a certificateless fully homomorphic encryption scheme is presented based on Learning With Errors (LWE) problem. The scheme builds the connection between the user’s identity and its public key with the trapdoor one-way function with preimage sampling so that the certificates are no longer necessary. The private keys are chosen by the users without key escrow. In the random oracle model, the security of the scheme strictly reduces to hardness of decisional LWE problem.