Design And FPGA Implementation Of Real-Time Color Video Chaotic Secure Communication System

Chaos is an important scientific discoveries of the 20th century. Since 1963 Lorenz proposed the first chaotic system, research about chaos attracts attentions from domestic and foreign researchers. Chaotic systems in the past remain in the realm of theory study. Recently, more and more chaotic systems are put into application. Specifically chaotic science has a rapid development in recent years, more and more researches would like to study chaotic theory and applications. Chaotic system is internal random, bounded traversal and highly sensitive for initial system parameters, which matches the conditions of a good encryption system. Therefore, more and more chaotic systems were used to engineering application. However, in the past, the chaotic system is mainly limited to encrypt the audio and static image data, which have less demand of real-time performance. Because of the difficulty of processing large amount of real-time video data, researches about video encryption are relatively inadequate. It is inefficient to encrypt large amount of video data by software method. Therefore, in this paper, we propose to encrypt video data via FPGA technology, which is based on complete hardware method. Make use of parallel high speed feature of FPGA, we meet the real-time requirements of video capture, encryption and display. In addition, video data is processed by high-dimension chaotic sequence, which has large key space, high performance against statistic attack and differentia attack. What’s more, the system has synchronization feature. Consequently, the encrypted video data has a high security.In this paper, on the understanding and thinking of domestic and foreign chaotic application, we realized a chaotic algorithm on FPGA development board, and test the security of the system. The content of this whole paper includes:1. Improvement of traditional chaotic sequence generator. The sequence, which is generated by traditional chaotic system, is based on real number. However, it is better for FPGA to deal with integer. Thus, for real-time performance of encryption and hardware resource on development board, we need to improve the original algorithm. And two integer chaotic systems will be realized on the FPGA developing board. In the paper, design process is shown in detail.2. By improving the existing discrete chaotic system, we present the design process of real-time color video chaotic secure communication system. In addition, security of the improved system will be guaranteed by some secure analysis.3. Realization of video capture system with FPGA technology. We introduce design flow and structure of the system briefly. The whole capture system consists of four parts: initial module with AD chip, ITU656 decoder module, cache module and VGA display module. At last, use a top-level module to piece the well-packed module together, fulfill the top-to-bottom design of video capturing system based on FPGA.4. Encryption and decryption of video data with chaotic sequence. Taking advantage of parallel operation, finite state machine and pipeline structure of FPGA technology, video data is encrypted by chaotic sequence, and process of encryption system is demonstrated in the paper.