Efficient Data Access Control for Cloud Computing With Large Universe and Traceable Attribute-Based Encryption

Ciphertext-policy attribute-based encryption (CP-ABE) schemes provide fine-grained access control for the data stored in cloud computers. However, commercial CP-ABE applications need a new encryption scheme for providing two properties such as: supporting large universe attribute and traceability. First, a large universe attribute allows the attribute authority to use any number of attributes in the system. i.e., the attribute universe is dynamic, and it is not fixed at the setup phase. Second, traceable CP-ABE systems trace the dishonest users who intentionally leak the private key for their profit. In this article, a large universe CP-ABE system with white box traceability has been proposed. The attribute universe of the proposed technique is exponentially larger, and it is polynomially unbound. Further, this technique will trace the identity of users who involve in malicious activities. In addition, the proposed scheme can express any kind of monotonic tree access policies into linear secret sharing structure (LSSS). Compared with the existing schemes that are presented to achieve the same property, proposed scheme has achieved better experimental results and so it is applicable for commercial applications.