الفهرس 
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Abstract
Recently, the necessity for secure image storage and transmission over public networks has been increased for essential uses and sharing purposes, there is a big challenge to protect the image and hide information from unauthorized users, especially in sensitive fields like military, politics, economics, medical and education. These digital images need to be protected from unauthorized persons. We need to encrypt these contents of the image, store and transmit them over an unsecured network. Encryption of images is different from that of texts due to some intrinsic features of images such as bulk data capacity, the high correlation among pixels, and high redundancy, which are generally difficult to handle by traditional methods. Unfortunately, most of the traditional cryptosystems cannot fulfill all the requirements of image encryption due to intrinsic characters, being time-consuming, and recovering images in the original image, due to more pixels replication and strong correlation between adjacent pixels. This thesis focuses on protecting digital images by using developed chaos-based encryption/decryption algorithms. We propose a new image encryption scheme based on parallel fuzzy multi modular chaotic logistic maps (PFMM-CLM). The main idea of the proposed system is to exploits the chaotic behavior of reported modular chaotic logistic map to design parallel multi modular chaotic logistic maps (PMM-CLM) to achieve a highly Lyapunov exponent values and completely chaotic behavior of the bifurcation diagram. In addition we utilize the fuzzy sets theory as fuzzy logic selector of the output of proposed PMM-CLM in order to increase the secure parameters of proposed scheme, also we introduced a Controllable Iterative Arnold Cat map (CI-ACM) based on the proposed PFMM-CLM to enhance the confusion concept. The proposed PFMM-CLM has been evaluated as a pseudo-random number generator (PRNG). The randomness test results indicate that system has better performance and satisfies all randomness tests. Due to excellent chaotic properties and good randomization results, we used the proposed PFMM-CLM for the image encryption application. Simulation and security analysis of our proposed encryption algorithm proved that it has an efficient method and a secure way for real time image encryption.