Provably Secure Threshold-Based ABE Scheme Without Bilinear Map

In several distributed environments, users can decrypt a secret message using a certain number of valid attributes or credentials. Attribute-based encryption (ABE) is the most promising technique to achieve such fine-grain access control. In recent years, many ABE schemes have been proposed, but most of them are constructed based on the concept of pairing and secret sharing scheme. This paper aims at presenting a pairing-free threshold-based ABE scheme (PT-ABE) over multiplicative group. The propose work is secured under the standard decisional Diffie-Hellman (DDH) assumption, and both error-tolerant and collusion-free. The scheme does not consider random oracle operation to prove its security. We compare the PT-ABE scheme with other relevant ABE schemes and find that our scheme is much more efficient and flexible than others. Besides, we propose a protocol based on PT-ABE scheme and show that PT-ABE is perfectly suitable in cloud environment to provide cloud security. To the best of our knowledge, the proposed scheme should be implemented in real- life distributed scenarios, as it is well secured, flexible and perform better than existing ones.