A Quantum Key Distribution System for Secure Communication in Electric Vehicle Smart Charging Network

[0024] Quantum key distribution, based on the basic principles of quantum mechanics, unconditionally securely distributes keys between two directly connected points. Taking the most classic BB84 protocol as an example, the protocol shares 4 quantum states to form two sets of orthogonal bases, and each set of orthogonal bases is also a set of measurement bases. The correct result can only be obtained by using the same group of measurement basis to measure the quantum state. The specific communication process is as follows: the sender of the key randomly selects one of the four quantum states, and sends it to the receiver through the quantum channel, the receiver randomly selects a measurement base to measure, and obtains a result, both parties record their own The selection and measurement results are compared with each other through classical channels, and the results of those wrongly selected measurement bases are deleted. If necessary, the final key can be established between the sender and the receiver after the last remaining random sequence has undergone steps such as "secrecy amplification".

[0025] The basic principle of quantum mechanics ensures that any eavesdropping behavior in the quantum circuit can be detected by both the transceiver and the transmitter, thereby ensuring the safe distribution of keys. At the same time, the introduction of the decoy state method and the improvement of the performance of optical devices have greatly increased the rate of key distribution. The rate of key distribution between two points 100 kilometers apart can reach 1.85Mbit/s, and as the distance decreases, the key distribution rate doubles. Based on the above characteristics, the data encryption method using quantum key distribution can efficiently and securely distribute encryption keys.

[0026] In the quantum key distribution system provided by the present invention, the key distribution unit in the quantum key distribution system is used to distribute encryption keys between adjacent nodes in the electric vehicle intelligent charging network. like figure 1 As shown, the operation management center in the key distribution unit and the key management module of the charging station are shown in the figure, which respectively include a processor, a key pool, an encryption/decryption module, and a light source or light detector. The processor is the core of the key management module and is responsible for the management of other functional modules, including accepting key distribution requests, establishing key distribution connections, and scheduling the key pool, etc.; the key pool is used to store keys, including The quantum keys distributed between adjacent nodes and the keys distributed between non-adjacent nodes; the encryption/decryption module uses the corresponding encryption key to encrypt or decrypt the information to be transmitted; the light source or photodetector is used to generate the The optical quantum signal used by the key distribution unit.

[0027] In addition to establishing the distribution of quantum keys between adjacent nodes, according to the actual situation of the electric vehicle intelligent charging network, a secure communication system for the electric vehicle intelligent charging network with a multi-level key distribution center is established in the technical solution of the invention. like figure 2 As shown, the electric vehicle intelligent charging network security communication system is divided into three levels: headquarters-level KDC, regional-level KDC, and charging station, between the charging station and the sub-operation management center, and between the sub-operation management center and the headquarters operation management center There are both quantum channels and classical channel connections. Quantum keys can be distributed between directly connected nodes and stored in a key pool. The distribution of keys between non-directly adjacent nodes mainly depends on the key distribution center KDC at all levels to cooperate.

[0028] To facilitate management, the headquarters-level KDC and regional-level KDC are located in the headquarters operation management center and sub-operation management center respectively. Between each sub-operation management center, and between the sub-operation management center and the headquarter operation management center, the data transmission volume is relatively large. In order to ensure the one-time encryption of the data encryption process, the required key distribution rate is also high. By using methods such as wavelength division multiplexing in quantum channels, the key distribution rate can be effectively increased to meet the key distribution requirements for data encryption.

[0029] The key distribution between different charging stations in the same area, and the key distribution between charging stations and sub-operation management centers are all completed by the local regional KDC. The key distribution of the charging station and the sub-operation management center can be initiated by the local regional KDC, and directly established through the connection of the quantum channel. Different charging stations in the same area, because there is no quantum channel connection, cannot directly distribute the quantum key. The distribution of the key mainly depends on the local district-level KDC to generate the encryption key and complete the relay. Similarly, the key distribution between operation management centers in different regions and between the operation management center in a certain region and the general operation management center is completed by the headquarters-level KDC.

[0030] like image 3 As shown, in region 1, there is no direct quantum channel connection between charging station 1 and charging station 2. If the two want to transmit data securely, they must first assign a secure encryption key. This task mainly depends on the region-level KDC in the region to complete. Charging station 1 and charging station 2 are respectively connected to the regional KDC of the region through quantum channels, and are assigned quantum keys K1 and K2 respectively. To distribute the key K between charging station 1 and charging station 2, the regional KDC uses quantum keys K1 and K2 to encrypt K respectively to obtain encrypted keys K'1 and K'2, the K' 1 and the K'2 respectively by and obtained, and sent to charging station 1 and charging station 2 respectively through the classic channel. Charging station 1 can use the quantum key K1 to decrypt the key K, and charging station 2 can use the quantum key K2 to decrypt the key K, so that charging station 1 and charging station 2 can distribute the security key without quantum channel connection K.

[0031] like Figure 4 As shown in the figure, management and control information communication is performed between the sub-operation management center and the headquarters operation management center. Sub-operation management center 1 and sub-operation management center 2 are respectively connected to headquarters-level KDC through quantum channels, and distribute quantum keys K1 and K2 respectively. To distribute the key K between the sub-operation management center 1 and the sub-operation management center 2, the headquarters-level KDC uses the quantum keys K1 and K2 to encrypt K respectively, and obtains the encrypted keys K'1 and K'2, so Said K'1 and said K'2 are respectively composed of and obtained, and sent to the sub-operation management center 1 and the sub-operation management center 2 respectively through the classic channel. The sub-operation management center 1 uses the quantum key K1 to decrypt the key K, and the sub-operation management center 2 uses the quantum key K2 to decrypt the key K, so that the security key K is distributed between two points without quantum channel connection.

[0032] It should be declared that the contents and specific implementation methods of the present invention are intended to prove the practical application of the technical solutions provided by the present invention, and should not be construed as limiting the protection scope of the present invention. Those skilled in the art may make various modifications, equivalent replacements, or improvements under the inspiration of its spirit and principles after reading the specification of this application. But these changes or modifications are all within the protection scope of the pending application.