关键词: 窄带物联网, 多授权机构, 隐私保护, 在线/离线加密, 外包解密

Abstract: Narrowband Internet of things (NB-IoT) is an important branch of the Internet. It can provide application-level services and achieve information intellectualization, relying on the powerful resource processing capability offered by cloud computing. However, due to the storage of data in different places, cloud platform service providers are not completely trusted. User data is exposed in a not completely secured environment and this brings many security problems, such as external malicious attack and cloud server collusion. Aiming at these NB-IoT’s issues like its terminal nodes are vulnerable to attacks, lacking in resources, limit in power consumption, a property-based cloud storage fast access control scheme is proposed. Under the background of multiple attribute authorities, an efficient and verifiable lightweight cryptographic encryption schemes is the goal. So using the idea of online/offline encryption and combining outsourced decryption technology, an online/offline and outsourced multi-authority ciphertext-policy attribute-based encryption scheme (OO-MA-CP-ABE) which can be secured from chosen-plaintext attack (CPA) is constructed. It improves the efficiency of the encryption and decryption algorithm while minimizing user’s computational overhead, quite suitable for terminal equipment with weak computing power and limited resources, and can further ensure the correctness of outsourced computing by verifying the algorithm as well. It also gives the security analysis of the lightweight NB-IoT application system under cloud computing environment, in order to ensure the flexible and extensible access control strategy and the confidentiality and privacy protection of user data during the resource sharing process. Finally, the performance analysis of the OO-MA-CP-ABE scheme is given, and compared with the existing schemes in terms of functionality, computational overhead and storage overhead.

Key words: narrowband Internet of things, multiple authorized institutions, privacy protection, online/offline encryption, outsourcing decryption