Enabling User-Policy-Confined VM Migration in Trusted Cloud Computing

The trusted cloud environment model, based on the trusted computing technology, provides cloud users the capabilities to remotely attest the trustworthiness of cloud service. But unlike physical machine, the virtual machine is migratory among cloud nodes constantly which makes it hard for cloud users to guarantee the Virtual Machine (VM) is running in a trusted cloud node and its migration is consistent with user's policy. Since the migration operation is entirely transparent to cloud users, it is hard for them to launch the remote attestation with the existing remote attestation scheme. To guarantee the migration of VMs is consistent with user's policy, we propose a User-Policy-Confined VM Migration Protocol (UVMP), which provides a new attestation scheme that addresses the limitation and enables VM migration to be controllable and verifiable by cloud users by introducing the Ciphertext-Policy AttributeBased Encryption(CP-ABE) into attestation field. To demonstrate that UVMP is practical, we incorporate it in the Xen opensource virtualization platform and implement UTVMS: UserPolicy-Confined Trusted VM Migration System. Our evaluation suggests that the attestation scheme cannot lead to the obvious performance on the VM migration by analyzing the migration latency. The attestation scheme can provide greater flexibility for cloud users to control their own VM migration.