Research On Security Mechanisms For AMI Networks Of Smart Grid

Smart Grid combines the advanced computer network communication technologies with the current power infrastructures to make the power grid more automatic and intelligent. Advanced Metering Infrastructures(AMIs) which achieves the two-way communication between the users and utilities is an important part of the Smart Grid. AMI networks are the foundations of demand response and energy management of the Smart Grid. The AMI networks involve the computer communication networks, information infrastructure networks and the social networks consisting of power users and utility staffs and these three networks interact with each other making the AMI networks have the characteristic of multi-domain interaction through information, physical and social domains. The human and physical factors have influenced the security and safety of AMI networks much more. The attackers can launch an attack from the information, physical or social domains and make comprehensive use of the network or physical attack techniques and social engineering methods to achieve cross-domain attacks.This paper analyzes the threats on the AMI networks in terms of multi-domain interaction, considers the influences of the human and physical factors towards the AMI networks and thinks of the restricted computing and storage resources of the many devices in the AMI networks. Researches on the AMI network security has been done from the following aspects:(1) In terms of multi-domain interaction, we analyze the threats the AMI networks faces in the information, physical and social domains respectively and the mutual influences between them. The APT attacks on AMI networks and the internal attacks are also analyzed. This part is the basis of the research on the AMI networks security.(2) Researches on the security mechanism of AMI networks focus on the routing security and intrusion detection:On the AMI network routing security, this paper considers the influences of the human and physical factors and analyzes the routing security requirements of the AMI networks. We study the RPL routing specification which is appropriate to the AMI networks. Secure key management is the foundation of the AMI network routing security. Based on the security layers and security domains, this paper designs the key management mechanism for the AMI networks which can resist the key leakage due to the human and physical factors. Based on that, the ECC and Hash algorithms are applied to achieve the confidentiality and authentication for the RPL and timestamp and checksum are applied to ensure the freshness and integrity of the routing information. The routing metric “packet forwarding rate” are designed to resist the black hole attacks and the grey hole attacks. Finally, the secure RPL routing is simulated on the J-Sim platform.On the AMI network intrusion detection, this paper focuses on the intrusion detection mechanism for the smart meter. Smart meters are key components of the Smart Grid and are also the interfaces for the information, physical and social domains to integrate with each other. This paper aim at designing a low-cost intrusion detection mechanism which can achieve physical detection for the smart meters. Firstly, the colored Petri net is used to depict the information flows among the physical components and their occurring conditions, based on which threat model for the smart meter is built. This paper proposes the concept of “spying domain” which is set in the physical storage of smart meters and collaborative intrusion detection is achieved in combination with the event logs and secret information. This intrusion detection mechanism targets on the false data injection attacks out of financial benefits and can detect the illegal reading and writing operation on the smart meter physical storages, which is not influenced by the updating of the smart meter software. Evaluation has been done to verify the efficiency and low cost of the smart meters.(3) On the multi-domain collaborative protection for the AMI networks, this paper proposes the concept of multi-domain collaborative protection, sets protecting strategies for the information, physical, social domain of AMI networks respectively and discusses the collaboration among those three domains. For the APT attacks on the AMI networks, multi-domain collaborative defense mechanism based on information sharing and security knowledge base are constructed to achieve multi-dimension analyzing, prediction and defensing against APT attacks.