SOME STUDIES ON INFORMATION SECURITY SERVICES AND THEIR MECHANISMS

Abstract

Multimedia is an emerging field that deals with different forms of information such as text, images, audio, sensor data and videos in an integrated manner. The advancement of devices to display multimedia and enabling them to transfer it from one location to another has resulted in increasing danger of their security services. Because of this, the secrecy of information is a critical component while transmitting or storing such information. In a hostile environment, security services are required as per the organizations and individuals need to protect their valuable information and resources. In this context, over the past two decades, dynamic systems and other practices have emerged with cryptography to provide security services like confidentiality, authentication, integrity and non-repudiation. With the advancement of technologies, various attacks are also updated with time. Hence comes the need for revised versions of mechanisms to resist such attacks. Several methodologies are implemented that are usually based upon symmetric and asymmetric key cryptography, which uses different algorithms. Billions of people are getting connected to each other through the Internet and exchange a large amount of personal information over the network. It becomes very important to secure such sensitive information from unauthorized users. This thesis work is primarily based on security services and their proposed mechanisms. This thesis begins with the study and comparative analysis of cryptography and several chaotic systems. Moreover, this thesis also discusses dynamic systems and other existing techniques. The complete study can be classified as an investigation and identification of several objectives, which are segregated into three major categories of inter-related problems. Every problem is addressed by proposing two different models for the solution. Since digital images are used frequently for communication, the first two problems are identified for digital images to achieve authentication and confidentiality in communication. The third problem is formulated to secure information in IoT networks. Based on these problems, real-time application for the examination system is proposed to preserve integrity in academic institutes, which was implemented during Mid Sem Examinations in DTU in 2018, which is addressed in chapter 6. Generally, image encryption techniques are based upon symmetric-key cryptography schemes, in which the original image is converted into a cipher image. Image encryption has a significant role in internet communication, multimedia systems, medical imaging, telemedicine, and military communication. Traditional cryptosystems are not suitable for images for

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encipherment purposes due to the statistical properties of an image. The objective of this research is to develop mechanisms to obtain security services. We have developed lightweighted cryptosystems for images and bulky-sized data to achieve suitable and excellent results. Digital images hold an important role in multimedia communications in the modern era, where multimedia transfers are done at a rapid pace. With the advent of internet-of-things (IoT) applications, these transfers have become a common practice. However, providing security to sensitive data is an essential and challenging task in case of IoT applications due to the limitations of the sensors in terms of memory and computational efficiency. Therefore, conventional ciphers cannot be applied in the IoT devices. Thus, two different methods have been proposed as follow: 1. Efficient light-weighted image encryption techniques (a) Model 1: An efficient image encryption scheme using elementary cellular automata with a novel permutation box. (b) Model 2: An efficient image encryption scheme based on an electromagnetic rotor machine. The second solution is based on partial or selective image encryption schemes. These algorithms are designed on the amount of encryption involved. So, it deals with the partial image encryption schemes. They are as follow: 2. Selective image encryption schemes (a) Model 1: DWT based image encryption scheme in frequency domain (b) Model 2: ROI based image encryption scheme in spatial domain In the third problem, we have also examined the security issues in the Internet of things (IoT) based devices. IoT devices have limited memory and fewer computational capabilities than other devices. It supports only predefined operations and performs a statistical calculation to identify environmental data, current demand, production cost, faults, etc. Steganography techniques based on frequency transform and chaotic maps are proposed to achieve confidentiality, integrity and authentication. The first solution is designed for smart meters, and the second solution helps to secure information of sensor data in the battlefield. 3. Steganography technique to secure information and integrity preservation of systems in IoT network

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(a) Model 1 - Chaos-based steganography technique to secure information and integrity preservation of smart grid readings (b) Model 2- Internet of Battlefield thing Security: A strategy to secure sensitive information using reversible steganography scheme. 4. We have designed algorithms to develop a real-time application that maintains academic integrity and prevents students' fraudulent behavior by the allocation of seats during examinations.