Study Of Image Chaotic Encryption And Decryption Via Bluetooth Wireless Transmission

With the rapid development of computer network technology, network transmission greatly improves people’s lives, because it has the advantages of being convenient and without geographical restrictions. Meanwhile, it has irreplaceable advantages to transmit data information via the Internet. Generally, image has the characteristics of high correlation between pixels, a big redundancy and so on when it exists in people’s mind. As we know, data is easily explored to being attacked by some risks, such as virus attack, information theft and so on when we transmit data via the Internet. Hence, it is significant to improve the security of image information by choosing the right digital image encryption technology and computer network technology. In recent years, chaos has a wide application in the field of information security. Chaos has natural concealment with the characteristics of non-periodic and similar-noise. Moreover, it is unpredictability because it is sensitive to the initial value and is not convergent. So, chaotic signal has the great advantage for secure communication. We realize chaotic digital image encryption via wired transmission which is stable and safe, however, wired transmission has the disadvantages of distance limitation, the ageing and so on. Therefore, it is vital to choose the appropriate wireless communication technology for realizing digital image chaotic secure communication.In this thesis, a kind of chaotic digital image encryption method based on Bluetooth wireless communication technology is proposed, with hardware implementation on TMS320VC5509A platform was demonstrated. Initially, we introduce some basic knowledge on chaos and digital image encryption technology, and design a digital image encryption algorithm based on chaotic cat map. This method can realize the encryption effect because chaotic cat map can scramble the image data locations. Then, we introduce the working principle of the Bluetooth protocols and Bluetooth serial port modules, and the transmissional methods between the master-slave Bluetooth modules. The main characteristic of this method is that it can realize point-to-point data acquisition and wireless transmission, which can successfully solve the disadvantage of cable transmission. Finally, on the TMS320VC5509A platform, we realize the digital image encryption based on chaotic cat map via Bluetooth technology and its experimental results are given. The results indicate that the scheme can achieve excellent encryption effect and can be more widely used in chaotic secure communication based on digital devices.