Formal security model for virtual machine hypervisors in cloud computing systems

The paper describes a formal security model for virtual machine hypervisors in cloud systems based on the graph theory. This model defines security properties and data access operations hierarchy inside virtual machines and hypervisors in the cloud. The proposed model makes it possible to formalize major security issues for cloud systems and define tasks for hypervisor security and methods to solve them as well as the security condition for the virtual machine hypervisors