It took place on Wednesday, 7/24/2024

Discussion of the master’s student (Saja Abdel Kazem Abdel Hassan) in the department council hall about her thesis tagged:

HYBRID DIGITAL/OPTICAL ENCRYPTION OF MULTIPLE COLOR IMAGE USING MEMRISTIVE CHAOS

AND COMPRESSIVE SENSING

Hybrid encryption of multi-color images using two chaos-based techniques

Memristors and piezo sensing

The discussion committee consists of the gentlemen whose names are listed below:

Prof. Sinan Hossam Mahdi / Ministry of Higher Education and Scientific Research / Department of Research and Development. President

Prof. Israa Badr Nasser / Al-Nahrain University / College of Engineering. Organically

M.D. Ethel Nofal Muhammad Taher / Al-Nahrain University / College of Engineering. Organically

Prof. Dr. (Experienced Professor) Raad Sami Fayyad / Al-Nahrain University / College of Engineering. Member and supervisor

ABSTRACT

With the fast growth of multimedia technology and the Internet, the need to protect information becomes increasingly critical. Image security has become more important, and image encryption being a powerful and straightforward method. It can be applied using digital, optical, or hybrid techniques. The main challenge is to design a high-speed, highly secure hybrid encryption system for multiple color image (MCI) that utilizes advanced techniques like high-order memristive chaos and compressing techniques. This thesis addresses this challenge.

 An eighteenth-dimensional (18D) memristive chaotic generator characterized by grid multi-double-scroll (GMDS) attractors is proposed. The chaos has the highest chaos dimension reported in the literature for image encryption purposes. The generator produces an extremely rich and complex-dynamical behavior with three positive Lyapunov exponents. The chaotic sequences are used to assist the operation of proposed hybrid digital/optical encryption and decryption systems for MCI. The encryption system consists of a digital encryption subsystem (DEsS) cascaded with an optical encryption subsystem (OEsS) which are controlled by six and twelve chaotic sequences, respectively. The DEsS is implemented using four sequential stages (compressive sensing, scrambling, DNA encoding, and diffusion). The OEsS works parallelly on the RGB components of the digital encrypted image and implemented using double-chaotic phase encoding in Fourier, fractional Fourier, and gyrator optical transforms domains, respectively. All the used methods work interactively to increase the security level and robustness of the proposed encryption system.

The simulation results show that the proposed encryption system works very satisfactory even with a 64-image input (plain) template. The entropy factor reaches 7.9997 and 7.9998 for encrypted single and multiple color images, respectively. The key space of the proposed system is 2 ²⁵⁵¹ which is the highest among other image encryption systems reported in the literature. These results prove the robustness and high security of the proposed encryption system.

The student has met the requirements for the certificate