Implementation Of Chaotic Systems Based On FPGA And Its Application In Multi-Media Secure Communication

With the rapid development of information technology,the security of multimedia data such as images,audios and videos are more and more important.How to ensure the security of multimedia data has become an important research topic.Different from traditional text data,multimedia data has the characteristics of huge data capacity and high redundancy,which makes it difficult to effectively protect by using traditional encryption methods.In order to cope with this challenge,researchers try to explore new methods of multimedia secure communication.The chaotic secure communication system combining chaos theory with traditional encryption algorithms has received extensive attention.Due to the unique characteristics of chaotic systems like extreme sensitivity to initial states and system parameters,pseudo-randomness,aperiodicity and ergodicity,the multimedia data can be quickly and efficiently encrypted by chaos-based secure communication systems.The research background and the significance of chaotic-based multimedia secure communication systems are provided.Then the recent research status and development trend of chaotic secure communication at home and abroad are enumerated and summarized.This paper aims to complete two kinds of chaotic multimedia secure communication systems: a voice-secure communication system based on a digital programmable multi-scroll chaotic system and a video-secure communication system based on a grid multi-wing chaotic system,and realize them in hardware platform.The works of this paper are as follows:(1)A novel controllable multi-scroll chaotic system is introduced.The number of chaotic attractors in this system can randomly change during communication which improve the randomness and complexity of the system,making the system more suitable for use in secure communication systems.Besides,a novel gird multi-wing chaotic system is introduced in this paper.Different with the gird multi-wing systems in the existing researches,the new system can generate gird multi-wing attractors with simple mathematical struct,which makes it easier to be implemented in digital systems like FPGA(Field programmable gate array)platforms.(2)A real-time chaotic audio secure communication system is designed based on the controllable grid multi-scroll chaotic system and the feedback-driven-response synchronization principle.The system can collect,encrypt,transmit and decrypt audio signals in real time.The hardware implementation of the system is realized by using low-cost FPGA platforms demonstrate the feasibility of this system.(3)A real-time video secure communication system based on the gird multi-wing chaotic system is designed.In order to improve the security of the system,the state variables of the chaotic system are post-processed by mixing and truncation of the low-effective bits.The ciphertexts of the three color channels are fed back to the chaotic system respectively,which improves the system's ability to resist the selection plaintext attacks,making the relationship between ciphertext and chaotic systems more complicated,and the system is more difficult to decipher.The chaotic video secure communication system designed by the FPGA platform is provided in detail.The hardware system can transmit and display the video data collected by the camera in real time.(4)In order to ensure the security of the system,some commonly used secure analysis methods like key space analysis,statistical characteristics analysis,plaintext sensitivity analysis,key sensitivity analysis and the NIST random number test suite are used to analyze the security performance of the designed chaotic secure communication system.