This work presented an analysis of the passive eavesdropping attack of two intruders on the original pingpong protocol with pairs of entangled qubits. A general recursive expression is obtained for the probability of detecting an attack made by random intruders number. It is shown that an increase in the number of intruders in a quantum channel leads to an increase in the probability of their attack detection by legitimate users.

The article deals with the importance of the cyber hygiene in the relationship between the employer and the employee. Attention is paid to such aspects as employee cyber hygiene when working with company-own data and information. An experiment was conducted in a real company. The current state of cyber hygiene employees of the organization was studied and analyzed. The methods of counteracting and protection in case of violation of the rules of cyber hygiene by the employee are offered. The ways of getting additional information about the employee (also the potential one) are described for analyze of the digital identity. Some open state registers are analyzed for information about a person who would be useful in terms of forming a psychological portrait of the employee. Ways to obtain information from an employer company are described. Also attention is paid to the importance of cyber hygiene in shaping the company's image in the market.

A new quantum secret sharing protocol based on the ping-pong protocol of quantum secure direct communication is proposed. The pairs of entangled qutrits are used in protocol, which allows an increase in the information capacity compared with protocols based on entangled qubits. The detection of channel eavesdropping used in the protocol is being implemented in random moments of time, thereby it is possible do not use the significant amount of quantum memory. The security of the proposed protocol to attacks is considered. A method for additional amplification of the security to an eavesdropping attack in communication channels for the developed protocol is proposed.

Protocols of data delivery in delay-tolerant networks with a low sensibility to the delays of signal and control data and to the intermittent connection (Delay/Disruption-Tolerant Networks – DTN) are considered in work. DTN (both for real-time and for non-real-time applications) have high requirements and strict constraints on delay, packet loss, and energy consumptions. The comparative analysis of parameters of different protocols of delivery of information in DTN is conducted. A mathematical model for quality of service (QoS) route determination is proposed. We suppose that any DTN sensor is enable to determine the optimal bundle of paths for minimising resource use while satisfying the required QoS constraints. The proposed mathematical model is grounded on the Lagrangian relaxation procedure introduced for approximately solving a large linear programming problem with NP-complexity. A lower bound on the value of the objective function on some set to define critical parameters and appropriate objective functions for controlling the adaptive QoS of constrained route discovery process is received. Performance trade-offs between QoS requirements and energy efficiency were simulated using Saaty Analytic Hierarchy Process. The proposed approach improves the network energy saving due to reducing energy consumption and decreasing average end-to-end delays within the DTN via optimised resource sharing in terminal and intermediate nodes compared with existing routing algorithms.

The article is devoted to the development of a digital image compression algorithm. Image compression is a type of data compression applied to digital images, to reduce their cost for storage or transmission. Algorithms may take advantage of visual perception and the statistical properties of image data. We will consider a lossy compression algorithm. The new algorithm is based on multiscale decomposition with a spline as a basis function. In the process of multiscale analysis, when constructing a spline, we should take into account analytical links. The application of this approach give an increase in the compression ratio with the same quality of compressed images.

The paper proposes a new cryptographic key exchange method. The basic idea of the proposed method is to use a permutation of a given set as a transformation object. The mathematical background of the method is the property of permutations to be decomposed into the product of disjoint cycles, the property of unique factorization of the product of disjoint cycles raised to the powers smaller than their order, and the complexity of factorization of the product of permutations whose cycles are noncommutative. The conditions to be met by the transformation parameters are defined. The concepts of cycleand block-noncommutative permutations are introduced. These properties of two permutations known to all participants in information exchange are sufficient for the correct operation of the method. The key space cardinality of the values of cycles’ exponents of two open permutations is investigated. It is shown that this cardinality is maximized if the disjoint cycles in the decomposition of open permutations are 3-cycles. The block diagram of a cryptographic system that implements the proposed method is investigated. Its work is described. The proposed method and system make it possible to generate a cryptographic key for information factorial coding without using a secure communication channel. They can also be used to form a non-permutation key.

In today's world, it's almost impossible to find a sphere of human life in which information technologies would not be used. On the one hand, it simplifies human life - virtually everyone carries a mini-computer in his pocket and it allows to perform many operations, that took a lot of time, in minutes. In addition, IT has simplified and promptly developed areas such as medicine, banking, document circulation, military, and many other infrastructures of the state. Nevertheless, even today, privacy remains a major problem in many information transactions. One of the most important directions for ensuring the information confidentiality in open communication networks has been and remains its protection by cryptographic methods. Although it is known that traditional cryptography methods give reasons to doubt in their reliability, quantum cryptography has proven itself as a more reliable information security technology. As far is it quite new direction there is no sufficiently complete classification of attacks on quantum cryptography methods, in view of this new extended classification of attacks on quantum protocols and quantum cryptosystems is proposed in this work. Classification takes into account the newest attacks (which use devices loopholes) on quantum key distribution equipment. These attacks have been named <; <; quantum hacking>>. Such classification may be useful for choosing commercially available quantum key distribution system. Also abstract model of eavesdropper in quantum systems was created and it allows to determine a set of various nature measures that need to be further implemented to provide reliable security with the help of specific quantum systems.

A cryptographic security scheme is proposed for a subsystem of the integrated computer-aided system that is intended for holding elections and counting the election returns. The main idea is to use two modern quantum cryptographic technologies: quantum bit commitment and quantum secret sharing. The scheme of information security of vote count procedure, and also the quantum bit commitment protocol and the quantum secret sharing protocol, are described. Using the protocols of quantum cryptography increases security of the computer-aided voting system on comparison with protocols of usual classical cryptography.

In this paper the methods of data protection for developed by authors earlier multichannel system of quantum secure communication are proposed. These methods allow closing the intercepted data from the unauthorized user. The simulation model of quantum secure communication system on optical fiber is developed. This model depends on three parameters: probabilities of an error in the fiber optic channel, time of detection of unauthorized connection to the fiber optic line and transmission rate. Results of modeling for two methods of data protection are presented.

A cryptographic security scheme is proposed within the frame of a subsystem of the integrated computer-aided system that is intended for holding elections and counting the election returns. The solution is based on two quantum technologies of cryptographic security: quantum bit commitment and secret sharing

This work was devoted to the development of method for improving security to eavesdropping attacks in quantum direct communication protocols.

In this paper the non-quantum method of security amplification for the ping-pong protocol with many-qubit entangled Greenberger-Horne-Zeilinger states (GHZ-states) is proposed. This method can be used in quantum cryptography and consists in invertible hashing of classical message blocks. The necessary sizes of matrices for hashing of message blocks are calculated at some values of the protocol parameters. The proposed method does not require the presence from legitimate users of any pre-established keys. Thus, the main advantage of the quantum secure direct communication protocols, namely the lack of necessity to distribute of secret key remains valid at usage of the proposed method.

In this paper the non-quantum method of security amplification for the ping-pong protocol with many-qubit entangled Greenberger-Horne-Zeilinger states (GHZ-states) is proposed. This method can be used in quantum cryptography and consists in invertible hashing of classical message blocks. The necessary sizes of matrices for hashing of message blocks are calculated at some values of the protocol parameters. The proposed method does not require the presence from legitimate users of any pre-established keys. Thus, the main advantage of the quantum secure direct communication protocols, namely the lack of necessity to distribute of secret key remains valid at usage of the proposed method.

The main features of information security are confidentiality, integrity and availability. Only providing these all gives availability for development secure telecommunication systems. Confidentiality is the basic feature of information security, which ensures that information is accessible only to authorized users who have an access. Integrity is the basic feature of information security indicating its property to resist unauthorized modification. Availability is the basic feature of information security that indicates accessible and usable upon demand by an authorized entity.

In this paper, the systematisation and classification of modern quantum technologies of information security against cyber-terrorist attack are carried out. The characteristic of the basic directions of quantum cryptography from the viewpoint of the quantum technologies used is given. A qualitative analysis of the advantages and disadvantages of concrete quantum protocols is made. The current status of the problem of practical quantum cryptography use in telecommunication networks is considered. In particular, a short review of existing commercial systems of quantum key distribution is given.

In this paper, the systematisation and classification of modern quantum technologies of information security against cyber-terrorist attack are carried out. The characteristic of the basic directions of quantum cryptography from the viewpoint of the quantum technologies used is given. A qualitative analysis of the advantages and disadvantages of concrete quantum protocols is made. The current status of the problem of practical quantum cryptography use in telecommunication networks is considered. In particular, a short review of existing commercial systems of quantum key distribution is given.