A group key-policy attribute-based encryption with partial outsourcing decryption in wireless sensor networks

Outsourcing decryption that enables the authorized users to obtain the original data without decryption computation is crucially important for wireless sensor networks in public data center. The existing outsourcing decryption schemes have been designed based on key-policy attribute-based encryption. The security of outsourcing decryption cannot be guaranteed, because the data center is not loyal, and existing schemes have high computational complexity and energy consumption. In this work, a novel partially outsourcing decryption scheme is proposed to guarantee data security and computational efficiency for resource-constrained sensor nodes and terminal equipments. According to the attributes of cluster nodes in the proposed scheme, the encryption secret key is encrypted based on group key-policy attribute-based encryption and sent to data center, and authorized users who satisfy the attributes of the ciphertext can obtain the secret key to decrypt the ciphertext. Furthermore, in order to reduce the decryption overhead for users, the authorized users can simply decrypt the transformation ciphertext that is partially decrypted by the data center using token key. Compared with the previous decryption schemes, the proposed scheme efficiently decrypts ciphertext and enhances security of the data. The simulation results also indicate that the proposed scheme is efficient in terms of energy consumption and computation by comparing to previous work. Copyright © 2016 John Wiley & Sons, Ltd.