Research On Secure Communication And Anti-jamming Technologies For Wireless Devices In Smart Grid

The smart grid is a complex cyber physical system(CPS)that integrates advanced sensing,communication technology with the physical processes in the power grid.It realizes bidirectional flow of electricity and information between the power utility and the users based on the traditional power system.As the core components of the smart grid,the smart terminal devices are the interface for interactions between smart grid's cyberspace and physical space.And as the implementation scenarios of smart terminals keep expanding,more and more wireless smart terminals are intro-duced into smart grid.While bringing the sensing and control capabilities to the smart grid,the smart terminals also become the entries of malicious attacks.For example,an attacker can jam the communication between smart terminals or change the meter readings to cause estimation er-rors and wrong control decisions,such attacks may cause incalculable losses.The security issues brought by smart terminals have been a research focus in recent years,yet defending the smart terminals from cyber attacks is challengingIt is of great significance to conduct research on the security issues caused by the smart termi-nals considering their import role in the smart grid.The goal of this paper is to develop technologies for securing the smart terminals from cyber attacks,and ensuring the confidentiality,integrity and availability requirements of the smart grid.We tackle the security problems of smart terminals from two levels,i.e.,device communication security and network transmition security.The main contributions of this paper are as follows1.As the smart terminals are vulnerable to data manipulation and replay attacks,we proposed a lightweight secure communication scheme and key management mechanism for the smart terminals in the smart grid.We took the smart meters in the advanced metering infrastructure(AMI)as our research target,and developed a method that combines HMAC and identity-based encryption(IBE)algorithm to secure the communication between smart meters.The developed method ensures the availability and efficiency of the communication.By map-ping the network address of each smart terminal into a public key,the binding between the smart terminal's identity and its public key is realized,and an IBE-based key management mechanism is proposed to enhance the security of the keys.The proposed mechanism is im-plemented on a Raspberry Pi,experiment on the Raspberry Pi shows the proposed mechanism can protect the confidentiality,integrity and authenticity of the transmitted data2.As the wireless interface of smart terminals is vulnerable to false base station attack,we proposed a radio signal fingerprinting based defense mechanism.We studied false base sta-tion attack against the GPRS-based smart terminals and proposed a defense mechanism.The proposed defense mechanism contains two steps,the first step is to detect malicious base sta-tions by checking the abnormality in the radio signal strength.The second step is to identify false base stations from the malicious base stations using the RF fingerprints technology.The smart terminals are forbidden from connecting to fake base station identified by the proposed mechanism,thus ensuring the security of the smart terminals3.As wireless routing protocol implemented in the smart grid is vulnerable to jamming attacks,we proposed security enhancement mechanisms.The IPv6 Routing Protocol for Low-Power and Lossy Networks(RPL),which is considered the most popular routing protocol for the smart grid,is vulnerable to jamming attack.We proposed a backup parent node selection mechanism based on the original preferred parent selection mechanism of standard RPL We proposed an available history vector(AHV)metric which reflects the fault correlation of different wireless links.The AHV metric is used to optimize the availability of the RPL based network under jammer attack4.As the wireless network composed of smart terminals is vulnerable to jamming attack,we proposed a defense strategy by localizing the jammer using a mobile tracker.We took the AMI network in smart grid as the implementation scenario,and use a mobile tracker to col-lect jamming signal strength measurements from smart meters,the measurements are then used to localize the jammer.To deal with noisy wireless environment of the smart grid,we used unscented Kalman filter(UKF)to estimate the jammer's state.And the interacting mul-tiple model(IMM)is used to estimate the jammer's motion and to revise the jammer's state estimation.The proposed method can localize the mobile jammer with limited number of observation nodes.