White-Box Traceable Attribute-Based Encryption with Hidden Policies and Outsourced Decryption

We address three practical problems of Attribute-Based Encryption (ABE) in this paper: performance, accountabil-ity and privacy. To do so, we present a novel Ciphertext-Policy Attribute-Based Encryption (CP-ABE) approach, which combines white-box accountability, hidden policies and outsourced decryption. In contrast to existing schemes, the proposed construction is not only more flexible, but also efficient enough to be used in more resource-constrained environments. This is because our construction is designed around efficient Type III bilinear maps and relies on a dedicated proxy to perform computationally ex-pensive operations. Furthermore, we provide an implementation of the proposed design. The conducted evaluation demonstrates the practicality of the approach under realistic assumptions.