الفهرس 
Chapter 1 IntroductionOnly 14 pages are availabe for public view
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Abstract
With the rapid advances in multimedia processing techniques, illegal disclosing and modification of distributed confidential secret data has become a common issue. The data related to nuclear activities can be categorized as a highly-sensitive data, which if illegally disclosed or modified, a severe adverse effect on the assets and operation of related nuclear facilities may occur. So, there is a high necessity to enhance the security of this category of data.
The proposed approaches in this thesis aim mainly to verify the integrity, and enhance the confidentiality of highly-sensitive data that may be archived or distributed between nuclear sites through an untrusted transmission medium.
A promising content-based image integrity verification scheme is presented. This scheme is suitable for verifying the integrity of images archived, or transmitted over insecure networks. The Discrete Cosine Transform (DCT) is utilized to embed a block-based mark for each block in another block according to a specific algorithm. At the receiver side, the reverse processes are executed to verify image integrity. The proposed scheme proved to have high sensitivity to detect any image modifications even they were visually imperceptible. To enhance the security level, the sensitive image is firstly encrypted, and then its integrity is verified using the proposed algorithm.
Another efficient integrity verification approach for recorded audio signals using DCT is proposed. This approach is based on a self embedding concept, which embeds block-based marks extracted from the same audio signal after being transformed into a 2-D format into other blocks according to a specific algorithm.
After the self-embedding process, the data is converted back into 1-D format, which represents a marked audio signal. The 1-D audio signal is converted into a 2-D format, and then converted back into 1-D format using the popular lexicographic ordering scheme utilized in image processing.
Reverse processes are executed to verify the audio integrity through the verification process. Based on the extracted audio signal properties, the integrity of the marked audio signal is evaluated. Different audio processing tasks and
attacks are implemented to examine the suitability of the proposed algorithm for verifying the integrity of highly-confidential recorded audio data. It is proved to have high detection sensitivity to detect any audio manipulations even they were inaudible.
The confidentiality of highly-sensitive nuclear images can be enhanced by multi-layer security algorithms, which exploit steganography and image encryption algorithms. The Least Significant Bit (LSB) steganography is utilized first with a 2-D Logistic map and second with a 2-D chaotic Baker map to constitute the two proposed multi-layer security techniques. Different image analysis and comparisons are presented to examine the applicability of the proposed algorithms for securing highly-sensitive images through transmission over noise-free, and noisy channels. Moreover, the proposed algorithms are applied for transmission over Orthogonal Frequency-Division Multiplexing (OFDM) channels, and their performance is evaluated under different conditions of fading environments. An equalizer is used to mitigate the impact of composite fading.
A multi-layer security model using Discrete Wavelet Transform (DWT) steganography with chaotic Baker encryption is proposed to protect highly-sensitive text based data records. The results reveal that it can be used efficiently for protecting highly-sensitive nuclear calculations and records (text-based data).