中文摘要：

云与移动计算的融合使用户能够更方便快捷地获取数据和服务，但是由于云平台和移动通信网络的开放性，如何在移动云计算环境下实现数据安全的访问和使用成为了亟待解决的问题。设计了一种基于多要素访问控制条件的代理重加密方案，包含系统模型、重加密算法及重加密密钥描述方法。基于该方案，云计算数据中心通过移动用户的访问请求，获取用户的客观访问控制条件，为用户生成相应的重加密密文，用户使用自身私钥即可对授权数据解密。在不增加用户密钥管理量的前提下，实现了移动云计算的多要素代理重加密。

英文摘要：

The integration of the cloud and mobile computing make users obtain the data and the service more conven- iently and efficiently. However, because of the openness of cloud platform and mobile communication network, how to implement the security access and usage of data for mobile cloud computing has to be solved urgently now. An multi-element access control condition based on proxy re-encryption scheme for the security requirement of mobile cloud computing was proposed, which was consisted of system model, algorithm and the description of re-encryption keys. In this scheme, data center in cloud obtained the objective access control condition of users based on their access request, and generated the corresponding re-encryption cipher for the users. The private key of the users could be used to decrypt the cipher. The scheme has achieved the target of multi-element proxy re-encryption without increasing the amount of users＇ private keys in mobile cloud computing.