Information Flow Control for Cloud Environments

Information flow control (IFC) on cloud environments is substantially affected by the features of multi-tenant and virtualization. For example, if multiple cloud applications executes on a cloud (this is the feature of multi-tenant), the information of one or more cloud applications may be intercepted by others. As another example, when the storage units assigned to a cloud application are re-assigned to others (this is caused by virtualization), the information of the original application stored in the storage units may be leaked to others. To solve the problems, we proposes a two-layered IFC model and a flushing function. The upper layer of the model isolates information of different cloud applications to prevent possible interception. The lower layer controls information flows in a cloud application to prevent information leakage. The flushing function flushes information in a storage unit when it is re-assigned to another cloud application. This prevents an application to obtain the information belonging to other ones