Research on Two Dimensional Code Encryption Method Based on Embedded Device

摘要

As the carrier of information storage, the generation standard and identification method of two-dimensional code are shared. A set of unified standards used, but without corresponding encryption measures, it is difficult to ensure that the two-dimensional code information will not be attacked and tampered by criminals in the process of transmission, resulting in information security risks. With the intellectualization of embedded devices, two-dimensional code has found an increasingly wide application, but its safety issue is becoming more and more prominent. This paper proposes a two-dimensional code encryption method based on embedded devices. In this paper, AES symmetric encryption algorithm which ensures both encryption and decryption speed and security is selected to encrypt the two-dimensional code. Key expansion with the traditional AES encryption algorithm has some flaws in that once a key in one of the rounds is intercepted, the previous and the following subkeys will be calculated through fixed algorithm. Random function is used to improve the generating algorithm of expanded keys, hence enhancing the anti-attack ability of the encryption algorithm. By putting random function and g function into Cloud for operation, the speed of encryption and decoding QR code of the embedded device is increased. The test results show that the system designed in this paper can effectively hide the information contained in the QR code picture, which shows that this method ensures high security.