KA2SE: Key-Aggregation Authorized Searchable Encryption Scheme for Data Sharing in Wireless Sensor Networks

As a promising technology, key-aggregation searchable encryption with constant computation overhead is especially suitable for sensor nodes with limited computation resources in wireless sensor networks. However, in most of the existing key-aggregation searchable encryption schemes, the authorized aggregation key is generated in a deterministic way. As a result, these schemes suffer from “<i>Key Forge Attack</i>” and “<i>Trapdoor Forge Attack</i>” that we proposed and hence fail to support the security property as they claimed (which is an important goal to be achieved in key-aggregation searchable encryption schemes). To fix these flaws, in this paper, we identify the security challenges related to key-aggregation searchable encryption and propose a lightweight key-aggregation authorized searchable encryption scheme based on attribute-based encryption, called KA<inline-formula><tex-math notation="LaTeX">$^{2}$</tex-math></inline-formula>SE. It enables a data owner to share encrypted data with an authorized query user by issuing only a single authorized aggregation key, and the authorized query user only needs to submit a single trapdoor to the cloud server to perform keyword search. We formulate the security definitions for KA<inline-formula><tex-math notation="LaTeX">$^{2}$</tex-math></inline-formula>SE and prove its security. Finally, empirical evaluations demonstrate that KA<inline-formula><tex-math notation="LaTeX">$^{2}$</tex-math></inline-formula> SE is computationally efficient in comparison with existing schemes.