Privacy-Preserving Digital Rights Management in a Trusted Cloud Environment

We present a privacy-preserving DRM scheme for a (future) cloud computing software market. In such a market, applications are packed into virtual machines (VMs) by software providers and the VMs can be executed at any computing center within the cloud. We propose the introduction of a software TPM as a container for VM-specific keys within the VM that moves around with the VM within the cloud. The software TPM is coupled to a virtual TPM at a computing center to constitute the root of trust for a local DRM enforcement system within the VM that checks the license before each application execution. This allows flexible price models, e.g. execute at most n times-like models. Users have proof that their personally identifiable information, stored and processed within the VM at a computing center, cannot be obtained by the computing center. A feature of our solution is that neither software provider nor computing center are able to build usage profiles of the software executions.