Digital Chaotic Secure Communications Systems Based on Adaptive Filter

• Main Authors: Jr-Fu Tan, 唐志斌
• Other Authors: S.C. Tsay
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/19460826394206832650

碩士 === 雲林科技大學 === 電機工程系碩士班 === 96 === The objective of this thesis is to explored in three important areas. At first, we introduce the characteristic of chaos and CSK technological of chaotic communication also introduce about cryptography.Next, we use the characteristics of replacing and iteration in cryptography, to random move the pixel of digital image. By using Arnold cat map, Baker map and Line map to move the image pixel, we can achieve the goal of image encryption. However, the such encryption methods could not change its image pixel histogram, so they might give a rise for the security of message. Therefore, we apply the property of chaotic signals produced by chaotic generator might be used to confuse with those moved digital image pixel. By observing the grayscale histogram, the property of pixel confusion can be achieved. Such a property can guard against the attack of statistical analysis, the performance of the various of chaotic state equations can be analyzed to obtain the best. In finally, we propose a scheme of the chaotic in digital communication system based on extend Kalman filter (EKF) and Adaptive transversal filter（ATF）, also transmit digital images in two systems to test the performances. Some digital images are transited to test and compare the system performances.