Protecting the Confidentiality of Virtual Machines Against Untrusted Host

Virtualization has been widely used in cloud computing systems to cut costs, and to provide dynamically scalable resources over the internet. Many ideas have been proposed to increase the security of the virtualized systems. But, a big unspoken assumption of these ideas is that the cloud users have to trust the cloud provider totally and unconditionally. In reality, however, this assumption can´t always hold water, host administrator, for one reason or another, is prone to illegally access the sensitive data stored in the guest virtual machines. In this paper, we put forward ideas to protect the confidentiality of virtual machines when the host administrator is untrusted. Based on virtualization environment, we define our threat model and analyze a set of security aspects which are of real-world concerns. Leveraging trusted computing technologies, we propose possible solutions to these security threats. The solutions can provide better confidentiality to cloud users, and have practical value to the future cloud construction.