Cryptcloud+: Secure And Expressive Data Access Control For Cloud Storage

CryptCloud+: Secure and Expressive Data Access Control for Cloud Storage

Abstract:

Secure cloud storage, which is an emerging cloud service, is designed to protect the con?dentiality of outsourced data but also to provide ?exible data access for cloud users whose data is out of physical control. Ciphertext-Policy Attribute-Based Encryption (CP-ABE) is regarded as one of the most promising techniques that may be leveraged to secure the guarantee of the service. However, the use of CP-ABE may yield an inevitable security breach which is known as the misuse of access credential (i.e. decryption rights), due to the intrinsic “all-or-nothing” decryption feature of CP-ABE. In this project, we investigate the two main cases of access credential misuse: one is on the semi-trusted authority side, and the other is on the side of cloud user. To mitigate the misuse, we propose the ?rst responsible authority and revocable CP-ABE based cloud storage system with white-box traceability and auditing, referred to as CryptCloud+. We also present the security analysis and further demonstrate the utility of our system via experiments.