单云服务器下的安全外包模幂运算  

Secure Outsourcing Modular Exponentiations with Single Untrusted Cloud Server

作　　者：王健一 王箭[1] WANG Jian-yi;WANG Jian(College of Computer Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)

机构地区：[1]南京航空航天大学计算机科学与技术学院,南京210016

出　　处：《计算机科学》2018年第11期155-159,共5页Computer Science

摘　　要：模幂运算是加密和签名系统中最基础的运算。由于模幂运算需要耗费很大的计算成本,因此很多方案提出将模幂运算安全外包给云服务器。但是,现存的大多方案都需要两个不共谋的服务器来实现安全的模幂运算,一旦服务器共谋,就会导致外包隐私数据泄露。此外,很多现有方案都假设底数和指数都是保密的,但这并不适合于大多数现实应用场景。通常来说,为了减轻计算负担,只有敏感消息才需要被保密。为了解决上述问题,分别提出了固定底数(底数公开、指数保密)和固定指数(指数公开、底数保密)的安全外包方案。在该方案中客户端只需要使用一个云服务器,从而避免了两个服务器的共谋攻击。理论分析及实验结果证明了该方案的安全性和高效性。Modular exponentiation is one of the most fundamental operations in many encryption and signature systems.Due to the heavy computation cost of modular exponentiation,many schemes have been put forward to securely outsource modular exponentiation to cloud.However,most of the existing approaches need two non-colluded cloud servers to implement the secure modular exponentiation,resulting in private data leakage once the cloud servers collude.Besides,most existing schemes assume both base and exponent in modular exponentiation are private,which does not conform to many real-world applications.Usually,in order to reduce the overhead of computation,only the sensitive messages should be privately protected.To solve the above problems,this paper proposed two secure outsourcing schemes based on fixedbase(public base and private exponent)or fixed exponent(private base and public exponent),respectively.In the proposed schemes,the client only needs one cloud server,thus avoiding collusion attack of two servers.Theoretical analysis and experimental results reveal the security and efficiency of the proposed schemes.

关 键 词：云计算 安全外包算法 模幂运算 单服务器 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]