The paper describe key points in algebraic bayesian network knowledge pattern implementation on C++ programming language. Knowledge pattern implemented as class that handle and store estimation for knowledge pattern elements. It also provide a couple of methods for processing knowledge pattern such as consistency update and a posteriori inference.
This paper presents an approach to a robust watermark extraction from images containing text. Data extraction based on developed approach to robust watermark embedding into text data, characterizing by conversion invariance of text data into an image format. The comparative analysis of existing approaches of steganographic data embedding into text data is carried out, their advantages and disadvantages are determined. The choice of groups to steganographic data embedding methods based on text formatting is justified. As an embedding algorithm is determined approach based on interline space shifting. The block diagram and the description of the developed algorithm of data embedding into text data are given. An experimental estimation of the embedding capacity and perceptual invisibility of the developed data embedding approach was carried out. An approach to extract embedded information from images containing a robust watermark, based on the existing limitations, has been developed. The Radon transform is chosen as the basic extraction procedure of embedded information, allowing to extract values of the interline spacing. An approach based on Gaussian mixture model separating to isolate the values of the bits was chosen. The limits of the retrieval of embedded data have been experimentally established, and the robustness of the developed embedding approach to the implementation of various transformations has been estimated. The following parameters of robustness developed approach are defined: rotation of an image containing embedded data at any angle; scaling an image with a scaling factor not exceeding 1.5; conversion to any bitmap format; the application of a median filter to an image with a convolution core limit of not more than 9, a Gaussian blur filter with a blurring limit not exceeding 8 and an average filter with a convolution kernel limit of not more than 5.
In this paper, we consider data transmission in “bad” channels with low snr and wideband interference. We propose a code construction based on frequency shift keying with fast frequency hopping having the rate of 1.5 bit per OFDM symbol. This code construction allows transmitting data in channels with string wideband interference and high noise levels, including with SIR equal to -30 dB and SNR equal to -9 dB. We also propose two new decoders that are more robust in regard to interference compared with the known OSN decoder. The first one, based on the Kolmogorov-Smirnov criterion, is more robust in case of very strong interference, while the second decoder has a wider working range for weaker interference and interference with narrower band. The computer simulation has shown that the proposed decoders have higher error correction efficiency than the previously known decoder. Thus, they can be recommended for use in real systems.
At present, the problem of creating methodological security of cyberphysical systems, in particular, the design and implementation of information security subsystems is acute. At the same time, the landscape of threats and vulnerabilities typical for a wide range of hardware and software technologies used in cyberphysical systems is extremely wide and complex. In this context, the security of application layer protocols is of paramount importance, as these protocols are the basis for interaction between applications and services running on different devices, as well as in cloud infrastructures. With the constant interaction of the systems under study with the real physical infrastructure, the challenge is to determine effective measures to ensure the integrity of the transferred control commands, as disruption of the performed critical processes can affect human life and health. The paper provides an analytical review of the main methods of data integrity assurance in management protocol of cyberphysical systems, as well as an overview of application layer protocols vulnerabilities widely used in cyberphysical systems of different types. Classical methods of data integrity assurance, new methods, in particular, blockchain, as well as the main directions of increasing the efficiency of data integrity protocols in cyberphysical systems are considered. Analysis of application layer vulnerabilities is carried out on the example of the most popular MQTT, CoAP, AMQP, DDS, XMPP specifications and their implementations. It is established that despite the presence of basic security mechanisms in all these protocols, researchers continue to regularly identify vulnerabilities in popular implementations, that often endangers critical infrastructure services. In the course of preparing the review of the existing methods of data integrity assurance for the examined class of systems, the key problems of these methods integration and ways of their solution were defined.