الفهرس | Only 14 pages are availabe for public view |
Abstract The amount of data is exploding due to the development of various technologies such as cloud, artificial intelligence, and big data. Along with the rapid development of wireless network technology such as mobile communication and multimedia display device technology, a lot of multimedia information is transmitted and shared through the Internet. Therefore, it is very important to protect images from problems such as illegal copying and illegal distribution. There has been an enormous increase in the distribution and archiving of Digital Imaging and Communications in Medicine (DICOM) medical images in recent years. With the widespread adoption of digital formats for medical records and the growing utilization of telemedicine services, large volumes of radiological and clinical imaging data are now routinely transmitted electronically and retained digitally. This reflects the vast gains in connectivity of healthcare networks and transition from traditional filmbased to computational medical imaging modalities across the industry. Secure exchange and long-term preservation of such sensitive patient information embodied in DICOMs has become mission critical as a result of the massive escalation in the digital dissemination and remote access to these important medical files. There are generally three main approaches to secure digital images - steganography, watermarking, and encryption. Steganography involves hiding information within other media, while watermarking embeds identifying signatures directly into image content. Encryption, on the other hand, is considered the most direct and efficient method. It ensures medical image security by converting the original, or plaintext, image into an unreadable form (cipher image) using a secret encryption key. In this thesis two proposed cryptosystems are designed and evaluated using security evaluation parameters. The first proposed cryptosystem is mainly based on a proposed technique called layered cellular automata (LCA), which enhance the security parameters for medical images either coloured or grey ones, the simulation results showed that the proposed system has the smallest processing time compared with other related schemes. Thus this cryptosystem can be adopted for real time applications. The second proposed cryptosystem based on non-uniform cellular automata technique in conjunction with DNA and JSMP map, the simulation results showed that, this encryption technique is an efficient technique, compared with other related techniques. For the two proposed techniques security parameters used to evaluate them are visual subjective analysis, entropy analysis, correlation analysis, differential attack analysis, histogram analysis, cropping attack analysis, and noise analysis. Finally, MIMO-OFDM wireless system was designed as a communication system for evaluating transmission of encrypted image through it. In the beginning, performance evaluation of four known chaotic based encryption techniques were adopted and compared when transmitting over MIMO-OFDM system. Then, the two proposed encryption schemes are evaluated under MIMO-OFDM wireless communication system. |