Cyber-attack against Global Navigation Satellite System （GNSS），which could induce mistake in timing and location information，is a novel threat in cyber space. The distributed dispersed meters and meter collectors are synchronized hierarchically by the satellite clock （GPS/BDS） in the head end of Advanced Metering Infrastructures （AMI）. Cyber-attack against GNSS could broadcast spoofed GNSS signal and force time synchronization device （TSD） to output erroneous time signal and disable AMI via operation mechanism of AMI. Based on in-depth analysis of operation mechanism of TSA and AMI，the way to implement time synchronization attack （TSA） in AMI and potential outcomes are analysed. Since error of time signal of satellite clock and Crystal Oscillator have complementary feature，A high-precision Oven Controlled Crystal Oscillator （OCXO） with cumulative error compensation is developed to identify time jitter of the satellite clock and help ride through sustained GNSS spoofing based TSA. Simulation on FPGA demonstrates the effectiveness of the proposed approach.

The cryptographic device generates a large amount of physical information such as electromagnetic，energy consumption，heat，etc. during encryption and decryption. The attackers use these physical information to perform a side channel attack on the cryptographic device and steal the key of the cryptographic device. In the case of a traditional simple power analysis attack of elliptic curve cryptography algorithm，the attacker recovers the key by manually identifying similar modules in the power consumption data of the double point calculation. But this way results in low attack efficiency and low attack accuracy. This paper proposes the SPAMD algorithm based on the time series of motif discovery. The algorithm realizes the automatic recognition of similar modules in the power consumption data of the double point calculation，and completes the conversion of the attack mode from manual recognition to automatic recognition. Experiment results show that SPAMD attacks have a significant improvement in efficiency and accuracy.

This paper presents a security assessment method for intelligent distribution transformer terminal unit（TTU）. Facing the applications of management and edge computing of distribution station area，the main security problems faced by the terminal are analyzed，and the key system indicators affecting the terminal security are extracted. Based on the mathematical model of information entropy，a stochastic forest mathematical model for terminal security situation assessment is constructed. By constructing a simulation example，the evaluation method is validated by the stochastic forest model. The results show that the proposed method can accurately identify and classify terminal anomalies，thus realize security situation assessment，and has a certain practical value.

First，the feasibility of a large-scale Internet of thing （IoT） attack is analyzed. Secondly，the test and evaluation model of demand attack is summarized，including the selection of transient and steady-state analysis tools，the protection measures involved and the parameters of the power network topology. Then the achievable targets are proposed，the composition of the attack sequences is studied，and several types of defense methods for responding to the demand attacks are proposed. The future research directions of such attacks are prospected in the end.

Smart meter is an important intelligent terminal in the measurement automation as the billing between the power company and the user，the traditional key management methods of intelligent terminals have some problems，such as low efficiency，large traffic and vulnerability to network attacks. Therefore，in this paper a key management method of intelligent terminals based on attribute base encryption and threshold secret sharing is proposed. Firstly，group authentication is used to authenticate the identity of smart meters，which reduces the number of one-to-one authentication communications. Then，（t，n）-threshold secret sharing technology is used in identity authentication，and attribute base encryption technology is used in key generation process to hide access structure and avoid leakage of smart meter information. Finally，there are many kinds of security threats in the network. Large data technology is used to mine the types of network attacks in order to quickly identify malicious attackers. The proposed method is simulated to verify its effectiveness. The simulation results show that compared with other technologies，the proposed method significantly reduces the storage burden of the system，improves the communication efficiency，and takes less time to identify malicious participants，thus ensures the security of key management.

At present，the safety protection of intelligent substation system is mainly implemented according to IEC 62351 standard. As an international standard，its safety technology mainly adopts international algorithm RSA，AES and digital certificate. In view of the security defects of communication in intelligent substation system，this paper proposes the following three solutions： 1） the communication between intelligent substation equipment based on IEC 62351 security mechanism should adopt the national security algorithm and dispatching digital certificate technology； 2） finding out the security risks of communication protocol IEC104 from dispatching master station to substation，putting forward the security transformation scheme and implementation method； 3） putting forward the communication protocol transformation schemes of station control layer and the process layer，then implementing them by the national security algorithm and scheduling certificate technology. The above security measures can ensure the real-time，reliability，confidentiality，integrity and availability of communication information and information resources in the station，stop illegal access of unauthorized users，and ensure the authenticity of identities of both sides of communication and the traceability of business data.

The fixed key and international cryptographic algorithm used in the traditional security bus have some uncontrollable factors and security risk in its design. A novel method of a security parallel bus is proposed to solve the security risk of traditional bus transmission. The key generation mechanism and ring oscillator physical unclonable function are designed in the security parallel bus. The key is generated by the SM3 algorithm with the input of the physical unclonable function and random number generator. The transmitting data on the bus is encrypted using SM4 algorithm. When encrypting，random numbers are used to fill plaintext for security reasons. These guarantee the security of bus data transmission. The bus implemented by this security mechanism can effectively resist the intrusive analysis，the replay attack，and the key cracking，thus ensure data security and confidentiality. At last，a bus encryption simulation platform is built up and the results are presented to validate the proposed method feasible.

As the core of intelligent power system construction，the rapid popularization of power-related chips has made its energy consumption a part of the energy consumption of power systems. For solving energy consumption issues for power terminal multi-core chip，firstly，based on the original task scheduling technology，this paper proposes an intra-task scheduling method that considers the probability distribution of task execution time； and uses mixed integer linear programming （MILP） to model the problem to obtain mathematical methods，to find the best scheduling solution. Finally，this paper verifies this method by establishing an experimental verification platform. The results show that the proposed method can save more than 30% energy consumption expectation than the traditional scheduling method.

This paper presents a hardware and software design scheme of a low voltage relay protection device integrated with measurement and control based on power dedicated multi-core heterogeneous chip. Combining with the basic structure of power dedicated multi-core heterogeneous chip，this paper describes the overall design of highly integrated low-voltage protection device integrated with measurement and control； designs the external interface of hardware for low-voltage all-in-one and standby self-switching devices； expounds the design of software system architecture and the allocation of device functions among multi-cores，focusing on power dedicated algorithm，real-time data flow based on pre-data processing and calculation of electrical parameters，and the abstraction of peripheral device access. The optimized multi-core communication mechanism is analyzed. Function and performance of the low-voltage protection device integrated with measurement and control based on the chip has been verified at the low-voltage side of a 110 kV substation，and the feasibility of the scheme is verified by the test results.

With the development of smart grids，the existing protection for power system terminals through physical isolation is not enough to deal with new threats. In this paper an embedded component solution with active immunity is proposed，which provides users with a complete trusted computing environment for trusted identity authentication，trusted storage，trusted metrics and trusted reporting. With the high-security national cryptography algorithm module as the root of trust，an active immune trusted computing technology solution covering secure boot，secure partition isolation，trust chain delivery mechanism and dynamic measurement mechanism is constructed. The proposed solution and the experiments prove that the solution can efficiently resist malware injection and secure boot attack.

The edge terminals of smart grid always generate a large amount of time series data，which is of great significance to the intelligent operation of smart grid. In order to protect the privacy of data and reduce the requirement of transmission bandwidth and delay，the data often needs to be stored locally. Due to the regularity of electrical equipment，the generated time series data has great redundancy，which provides a solution to the challenge of data storage at edge equipment. In this paper，an edge electricity data deduplication method is proposed based on dynamic time warping，which calculates the similarity between data to eliminate data redundancy and achieve the purpose of data deduplication. Finally，based on the real-world time series data of smart grid，the effectiveness of the proposed data deduplication method in edge computing security protection system is analyzed and verified.

Aiming at the protection of user sensitive information in smart grid terminals，and to counter the privacy inference attack on user sensitive information，this paper proposes an efficient similarity matching based data privacy-protection scheme for edge terminals in smart grid. First of all，this paper proves that the user’s sensitive information can be inferred based on the time series data prediction model. In order to resist the privacy inference，the FastDTW algorithm is used to identify the time series data related to sensitive information，and to achieve the purpose of privacy protection by disturbing the relevant data and reducing the inference accuracy. The experiment results show that the privacy protection method proposed in this paper can make the attacker unable to accurately obtain the actual power consumption of the user，thus effectively protect the user’s power consumption information.