The rapid development of the power Internet of Things (IoT) has greatly enhanced the level of security, quality and efficiency in energy production, energy consumption, and related fields. However, it also puts forward higher requirements for the security and privacy of data. Ciphertext-policy attribute-based encryption (CP-ABE) is considered a suitable method to solve this issue and can implement fine-grained access control. However, its internal bilinear pairing operation is too expensive, which is not suitable for power IoT with limited computing resources. Hence, in this paper, a novel CP-ABE scheme based on elliptic curve cryptography (ECC) is proposed, which replaces the bilinear pairing operation with simple scalar multiplication and outsources most of the decryption work to edge devices. In addition, time and location attributes are combined in the proposed scheme, allowing the data users to access only within the range of time and locations set by the data owners to achieve a more fine-grained access control function. Simultaneously, the scheme uses multiple authorities to manage attributes, thereby solving the performance bottleneck of having a single authority. A performance analysis demonstrates that the proposed scheme is effective and suitable for power IoT.

Power Internet of Things (IoT) is the application of IoT technology in the field of power grid, which can better control all kinds of power equipment, power personnel and operating environment. However, access to mass terminals brings higher requirements for terminal authentication and key management for the power IoT. And the traditional public key infrastructure (PKI) and identity-based public key cryptography (IB-PKC) exist the problems of certificate management and key escrow. Therefore, the paper proposes a novel authenticated key agreement scheme based on the certificateless public key cryptography (CL-PKC) mechanism. In addition, the proposed scheme is proven with the improved extended Canetti-Krawczyk (eCK) security model. Finally, the implementation of the authenticated key agreement protocol is given based on the actual application requirement of the power IoT, and the analysis and comparison of the simulation demonstrates that the proposed scheme has higher efficiency and would be suitable for the power IoT.

As a novel network security scheme, the zero trust model can effectively improve the traditional role-based access control model in the public network by continuous trust evaluation and dynamic authorization. As a private network for collecting the health status data of the power equipment, the terminals in the power Internet of Things (IoT) have the characteristics of fixed and controllable hardware, software, and users, and the main network security threat of the power IoT comes from the risk of terminals being damaged or forged. Therefore, based on the analysis of the key connotation of the zero trust and the security characteristics of the power IoT, this paper proposes a novel zero trust model and framework to synthetically evaluate the security status of the power IoT based on the behaviour and characteristics of the terminals. The analysis based on the stochastic Petri net and simulation results show that the proposed model can effectively address network security problems and significantly improve the level of security protection of the power IoT.