منصة الرسائل والاطاريح: تصميم وتنفيذ نظام اتصالات لاسلكي أمن ذو عشوائية مفرطة بأستخدام مجموعة بوابات قابلة للبرمجة

الخلاصة

Image encryption algorithms based on nonlinear systems (such as chaos and hyperchaos) are increasing rapidly because of the wide range characteristics offered by these systems such as unpredictable behavior, extreme sensitivity to initial conditions and system parameters perturbations. The design, simulation, and FPGA implementation of a secure wireless hyperchaotic communication system is presented using five different proposed algorithms. The design and simulation are carried out using Xilinx System Generator (XSG) while the FPGA boards are programmed with Very high-speed integrated circuit Hardware Description Language (VHDL). The first proposed algorithm is the design of three-dimensional Lorenz nonlinear system generator at the transmitter (Tx) and receiver (Rx) sides to be used as a high-speed chaos switching in order to switch between the designed hyperchaotic carriers where it can be employed in the XOR operation. The second algorithm involve the combination of different hyperchaotic systems using the XOR logical operation to construct a new multi-dimensional hyperchaotic system. The generated hyperchaotic system is used in the Tx and Rx to encrypt and decrypt the images. Peak Signal to Noise Ratio (PSNR) and Mean Square Error (MSE) between the original and encrypted images are calculated. The results are around 8 for PSNR and 1.3e4 for MSE, which indicated that the images are highly different. The number of pixels change rate (NPCR), and unified averaged changed intensity (UACI) are also calculated through this work, the NPCR has a value close to 100%, while UACI is close to 33%, which indicates that the algorithms are highly immune against the differential attacks. The third proposed algorithm is a cascaded hyperchaotic system generator based on chaos switching, where three different dimensional hyperchaotic systems are used and combined using high speed switch. The output of the speedy switch is controlled by the Lorenz chaotic system (first proposed algorithm). The mixture patterns of the hyperchaotic systems generate completely new binary bit streams that used for secure image-based communications. The UACI, and NPCR results are close to 33% and 100% which satisfied the conditions to stands against the attacks. The fourth proposed approach involves designing a new version of a five-dimensional hyperchaotic system with a sine wave as an input parameter to the ordinary differential equations to increase the randomness and unpredictability of the developed system. The proposed new system has been adopted to build a secure communication system for image encryption purposes which show a good performance. The calculated MSE and PSNR between the encrypted and plain images are closed to 1.57e4 and 6.25 respectively, which means that the images are efficiently encrypted. The last proposed approach involves constructing a new random binary bit stream generator to be utilized in the communication systems' transmitters and receivers based on the 1st, 2nd, 3rd, and 4th proposed algorithms. The system is meant to exhibit extremely unexpected behavior and randomness, making it ideal for secure image encryption/decryption. The histogram is computed to view the color distribution of the ciphered images which show a flat distribution which indicates efficient performance. All the designed algorithms are used and tested for RGB and gray scale images with different sizes (equal and unequal dimensions). All the designed algorithms are successfully implemented using FPGA PYNQ-Z1 zynq xc7z020 board with acceptable board resources utilization.