Bolohova N.M. Model, methods, and information technology for digital image authentication in user-oriented systems. - Qualification scientific work as a manuscript copyright.
Thesis submitted for the degree of Doctor of Philosophy in the specialty 126 "Information Systems and Technologies" (12 - Information Technologies) - Kharkiv National University of Radio Electronics, Ministry of Education and Science of Ukraine, Kharkiv, 2023.
The thesis is devoted to the current problem of the urgent task of developing information technology for confirming the right of ownership of digital images, utilizing modern trends in the field of digital watermarks and blockchain to create a new decentralized technology for confirming the right of ownership of digital images. In the thesis, based on theoretical and experimental research, the problem of constructing methods for generating distortion-resistant digital watermarks based on chaotic maps is solved, and an information technology for confirming the right of ownership of digital images is developed.
The aim of the thesis is to develop information technology for confirming the right of ownership of digital images, which utilizes modern trends in the field of digital watermarks and blockchain to create a new decentralized technology for confirming the right of ownership of digital images.
The object of research – the process of confirming ownership of digital images.
Research methods – system analysis, process approach – to study the processes that take place when securing copyright to a work, modelling, set theory – to describe the model of digital image authentication, steganographic methods – to implement the concealment of the very fact of using a digital image signature, which ensures the process of confirming ownership. Experimental studies were conducted in the laboratory and on real objects.
The scientific novelty of the dissertation is as follows:
1. For the first time, a comprehensive criterion for assessing the effectiveness of methods for embedding digital watermarks in images is proposed. This criterion, constructed considering key characteristics and the determination of weight coefficients, allows for a comprehensive evaluation of the effectiveness of the method of applying digital watermarks.
2. The method for reliable authentication of digital images with a high degree of protection has been improved. Reliability is achieved by hiding the DW not in the entire image but in its fragment, which is most suitable for concealing the image, and by applying obstructive codes as DW.
3. The method for enhancing the robustness of the stegosystem is improved by considering key indicators. The pseudoholographic coding method of digital watermarks described in the work is effective in countering all types of attacks considered, except for image rotation.
4. Methods for generating DW for digital images have been further developed. Specifically, methods for generating DW based on chaotic maps and additional filtration of the digital watermarks have been developed. The described methods are effective in ensuring the robustness of DW to local distortions. Research has shown that with 60% distortion of the image, it is possible to restore 90% of the DW.
5. The information technology for confirming ownership of digital images, based on blockchain technology and digital watermarks, has been improved to provide reliable guarantees of establishing copyright.
The thesis analyzes the current state of the problem and the peculiarities of tasks related to ensuring copyright and confirming the authenticity of digital images. Methods of applying digital watermarks to images are analyzed, and modern approaches to their implementation are presented.
A functional model of the process of increasing the stability of methods for embedding digital watermarks in digital images has been developed. This model is based on pseudoholographic coding and additional filtration of the digital watermark. The pseudoholographic coding method described in the work is effective in countering all types of attacks considered, except for image rotation. A comprehensive assessment of the methodology for improving the robustness of the method of embedding digital watermarks based on wavelet transforms has shown that its use improves resistance to various types of attacks by 20%.
The work presents an indicator for assessing the robustness of methods for applying digital watermarks, which takes into account all types of attacks and allows for a comprehensive evaluation of the robustness of the method of embedding digital watermarks. An experimental study was conducted on the proposed methodology.
