An architecture for overlaying private clouds on public providers

Organizations shifting to a public cloud infrastructure face potential hurdles regarding control and security, and must acquire a new set of best practices regarding developing and deploying to a cloud infrastructure. We propose a reference architecture for a virtual private cloud built on cross-provider ondemand compute instances, with a set of components, services, and algorithms to produce a managed platform that reduces the level of trust required for infrastructure-as-a-service (IaaS) providers, increases control and isolation, improves security and data protection, and allows architects, developers, and operations staff to deploy applications to the cloud using their existing body of knowledge and best practices. Two concrete architectures based on this reference are presented, and a prototype implementation is described and tested.