SC-DVR: a secure cloud computing based framework for DVR service

Typical digital video recorders (DVRs) have limited storage capacity, and it is not easy for them to share content among user devices. However, if DVRs are extended to the cloud-based infrastructure, conversion of content and sharing it among multiple devices can be made possible through the cloud´s computing power. To provide secure cloud computing service, appropriate measures are necessary to protect the computing processes performed on the content from inside and outside attackers. A content encryption scheme is a simple and effective way to protect content from attackers; however, if an encryption scheme is used, the user cannot use computing resources that can be used for media computation. This paper proposes a secure cloud DVR framework based on personal virtualization to securely provide various functions through cloud resources. The proposed scheme uses an input/output management unit (IOMMU), which serves as direct memory access (DMA) remapping for constructing secure personal virtualization. Using IOMMU, it is difficult for inside attackers to know which memory area is the actual memory of the target user. Therefore, secure computation in the cloud computing is possible through IOMMU. The proposed scheme uses an IOMMU based cloud computing to hide media computation from inside attacker, and a public cloud to increase efficiency.