Abstract: The government data cloud service platform is based on dynamic trust assessment.It can effectively promote inter connection and business collaboration between various departments of the government.It avoid the generation of information island through a unified cloud service interface and data standard. It helps to promote the development and reuse of the governments large data. The category of dynamic trusted evaluation include the trusted state of the host in the cloud service security management, the credibility of the virtual machine, the security level of the cloud service, and the behavior records of the cloud users. The government cloud data center and the application of government cloud business are provided to the outside world. In the security management, TCM trusted service is built into the traditional cloud service to manage cloud services. Trust relationship is transferred from trusted root to cloud host and government data cloud service. The trust value of cloud user behavior evidence is measured by ANP behavior matrix, and cloud user is established as a security mechanism for dynamic trust evaluation, and a secure and credible cloud service is provided for government data.

Key words: trusted computing, cloud service, dynamic evaluation, cloud security