Cloud computing provides a variety of services and interfaces, then cloud service providers render various services to users through these services and interfaces deployed in their physical machines, and finally users can use these services and interfaces at a low cost without needing to spend much money buying and maintaining IT infrastructure.Even though the use of cloud storage services can help enterprises cut down expenses,and improve availability and reliability, enterprises still have doubt about the confidentiality and integrity of the data stored by them in the cloud.If lots of confidential information needs to be stored in the cloud, it must be first ensured that the third-party platform is creditable, data is transmitted safely and access right is under control.This paper aims to improve the safety of encryption and the efficiency of retrieval by encryption technologies and related methods.