الفهرس 
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Abstract
In recent years, the world has been living the age of communications revolution which necessitates multimedia transmission in a secure manner. In this thesis, we investigate several image encryption and channel coding techniques. In order to design an effective scheme for secure image transmission over wireless networks that is able to secure the image besides being able to correct errors in the channel so that it improves the throughput in noisy environments, three different algorithms were proposed as follows:The first scheme proposed image encryption by a combination of the hybrid chaotic map. First, the Baker map is used to shuffle the positions of the image pixels in three different modes of operation cipher block chaining (CBC), cipher feedback (CFB), output feedback (OFB). Second, the shuffled image is encrypted by using our proposed Hénon chaotic map 4, and fractional Fourier transforms (FRFT) applied before the encryption.This process can achieve a large degree of randomization and it makes our proposed algorithm more sensitive to any change in keys or plainimage it has sensitivity to any small change in parameter r until 10-14. By analyzing our algorithm, we show that the key space of our algorithm is equal to 10128 so that it requires 4.3675 10111 years to attack.The second scheme proposed image encryption based on the development of a Hénon chaotic map using FRFT. This proposed scheme combines the main advantages FRFT, Arnold cat map for confusion and our proposed Hénon chaotic map 3 for diffusion. The proposed algorithm is compared with some different chaotic maps in several experimental tests. These comparison tests demonstrate that our proposed algorithm yields good result even better than RC6 and other chaotic maps in some cases and our proposed algorithm using Hénon map 3 gives the best result. Furthermore the entropy test shows that the average entropy for the test images is not less than 7.992.Furthermore, after analyzing the histogram and correlation between the adjacent pixels we show that our algorithm is robust against different types of attacks.The third scheme proposed is based on a combination of hybrid chaotic encryption,low density parity check (LDPC) code in a single algorithm to secure transmission of images over wireless networks. It uses the second scheme for image encryption and LDPC as a channel coding technique. Simulation results show that the proposed scheme enhanced the performance parameters and achieved both security and reliability of image transmission through the wireless channel. The proposed scheme suggests that for secure image transmission over wireless channels, it applies encryption prior to coding because of the shorter execution time than when encryption is applied after coding. Our proposed scheme gives good results in the reconstruction of the images at the receiver side image transmission over wireless channels, it applies encryption prior to coding because of the shorter execution time than when encryption is applied after coding. Our proposed scheme gives good results in the reconstruction of the images at the receiver side. Finally we can conclude that the proposed scheme is very effective for secure image communication over wireless noisy channels.We also introduce the use of the Hénon chaotic map in image security and propose four different developments of the Hénon chaotic map, with the goal to increase the available chaotic range of parameter r to be a very wide range. Increasing this range variation from [1.07, 1.4] to [0, ∞] makes the proposed algorithm more robust ag.