Design and Implementation of Virtual Private Services

Large scale distributed applications such as electronic commerce and online marketplaces combine network access with multiple storage and computational elements. The distributed responsibility for resource control creates new security and privacy issues, which are exacerbated by the complexity of the operating environment. In order to handle policies at multiple locations, the usual tools available (firewalls and compartmented file storage) get to be used in ways that are clumsy and prone to failure. We propose a new approach, virtual private services. Our approach relies on two functional divisions. First, we split policy specification and policy enforcement, providing local autonomy within the constraints of the global security policy. Second, we create virtual security domains, each with its own security policy. Every domain has an associated set of privileges and permissions restricting it to the resources it needs to use and the services it must perform. Virtual private services ensure security and privacy policies are adhered to through coordinated policy enforcement points. We describe our architecture and a prototype implementation, and present a preliminary performance evaluation confirming that our overhead of policy enforcement using is small.