Research On Data Encryption Technology Of Wireless Communication System Based On STM32

With the development in computer and communication technology, embedded systems have been developed rapidly, and widely used in various fields. The combination of embedded systems and wireless network technology enhance the communication capability between the embedded devices, which provides a convenient platform for realization of industrial remote monitoring and intelligent environment monitoring, et al. Therefore, it is necessary to make sure that the information is transmitted safely between the embedded devices.SM4 algorithm is the first block encryption algorithm to be used in the field of wireless local area network.It is easy to be realized in software and hardware and suitable for embedded devices.Although the SM4 algorithm has a high security in theory,it is still possible to be attacked. In order to improve the security of SM4 algorithm,we change the generation of the key and the S box which Implement the encryption and decryption both on the software and the embedded systems.In round function, the single S box is modified to two, and the parameters in the Key expansion algorithm are modified to get by randomly.We compare the SM4 with AES, and analysis these two algorithms in security and efficiency.The result shows that the improved SM4 algorithm takes a little time to improve the complexity of algorithm.In this paper, for wireless communication security between the embedded devices we present a scheme based on STM32 and μC/OS-II. The upgrade SM4 implements by software and transplants on the embedded system.We design the function of sending and receiver terminal.The sending is responsible for encryption information and sending them to the receiver by the wireless way. The receiver includes the embedded system and PC which realizes the wireless communication in the short-range or long-distance. The receiver is responsible for information processing.By the test, the system realizes the security of wireless communication network.It is safe for the short-range or long-distance communication, and also can be extended to the actual application needs.