Cloud computing is in a great conve

Cloud computing is in a great convenience to the user and enterprise use of inexpensive storage resources, software resources, computing resources. At same time, the biggest challenge facing or problems is from the aspects of security[4]. In cloud computing, users lose control of data and computation deposited in the cloud server. Whether the data is protected or the computing task is correctly executed are not sure, which lead to many potential risks and all kinds of security problems in many aspects. With the growing popularity of cloud computing, Cloud computing security problem has become one of the key problems affecting its development. The importance of safety problems showed a gradually rising trend, which has become an important factor restricting its development, and will influence the acceptance of users to cloud computing service. As a result, it will also further affect the development of cloud computing services.