Provable secure lightweight attribute-based keyword search for cloud-based Internet of Things networks

As more data from Internet of Things (IoT) devices is outsourced to cloud service providers, the need for secure and efficient fine-grained access control and data retrieving mechanisms will be increasingly pressing. Attribute-based keyword search (ABKS) is a promising tool to provide the required infrastructures. However, most of the existing ABKS schemes suffer from expensive computational overhead on the user side. This feature makes such schemes unsuitable for IoT applications as IoT devices usually have limited computational resources. To address this problem, we design a lightweight ABKS scheme called LW-ABKS. In our scheme, by performing a constant number of efficient computational operations, a data owner can generate a searchable ciphertext. Indeed, in generating a searchable ciphertext, the number of operations performed by data owners modeling IoT devices does not depend on the number of attributes in the access control policy. Moreover, in LW-ABKS, an authorized data user can retrieve the outsourced data files by performing very lightweight computational operations. We also provide security definitions for the new primitive and prove its security in the standard model and under the hardness assumption of the discrete logarithm and the decisional bilinear Diffie-Hellman problems.