中文摘要：

分析了移动云计算中弹性存储外包方案，指出该方案中基于共享方案（ShS）存在机密性和完整性缺陷，基于编码方案（CoS）和基于加密方案（EnS）存在完整性缺陷，同时给出针对缺陷的攻击方法．由此提出了改进安全协议安全共享协议（SShP）、安全编码协议（SCoP）和安全加密协议（SEnP），以克服原协议中存在的安全性缺陷．采用公钥加密和数字签名，对协议中核心数据加以保护．安全性分析表明：改进协议可确保用户数据的机密性和完整性，且在保持原方案架构的基础上具有更高安全性．仿真结果显示改进安全协议的通信开销和原协议相比没有明显增加．

英文摘要：

The resilient storage outsourcing schemes in mobile cloud computing are analyzed. It is pointed out that the sharing-based scheme （ShS） has vulnerabilities regarding confidentiality and integrity; meanwhile, the coding-based scheme （COS） and the encryption-based scheme （EnS） have vulnerabilities on integrity. The corresponding attacks on these vulnerabilities are given. Then, the improved protocols such as the secure sharing-based protocol （SShP）, the secure coding-based protocol （SCoP） and the secure encryption- based protocol （SEnP）, are proposed to overcome these vulnerabilities. The core elements are protected through public key encryptions and digital signatures. Security analyses show that the confidentiality and the integrity of the improved protocols are guaranteed. Meanwhile, the improved protocols can keep the frame of the former schemes and have higher security. The simulation results illustrate that compared with the existing protocols, the communication overhead of the improved protocols is not significantly increased.