Practical Verification of Data Encryption for Cloud Storage Services

Sensitive data is usually encrypted to protect against data leakage and unauthorized access for cloud storage services. Generally, the remote user has no knowledge of the actual data format stored in the cloud, even though a cloud server promises to store the data with encryption. Although a few works utilize data encapsulation and remote data checking to detect whether the sensitive data is protected securely in the cloud, they still suffer from a number of limitations, such as heavy computational cost at the user side and poor practicality, that would hinder their adoptions. In this paper, we propose a practical verification scheme to allow users to remotely evaluate the actually deployed data encryption protection in the cloud. We employ the pseudo-random number generator and present a data encapsulation solution, which can benefit users with significant cost savings. By imposing monetary rewards or penalties, our proposed scheme can help ensure that the cloud server stores data encrypted at rest honestly. Extensive experiments are conducted to further demonstrate the efficiency and practicality of the proposed scheme.