The existing methods of information delivery to the strategic and tactical management of many government agencies are expensive, not always reliable and efficient. Therefore, quantum cryptographic systems (QCS) have been actively developed in recent years. However, there are problems with the use of the QCS associated with the reliability of information transfer. First, the existing fiber-optic communication channels (FOCC) are not designed to transmit single-photon signals, which leads to the complexity of their cryptographic protection. The second is insufficiently methodically developed calculation of energy losses and errors in the evaluation of the characteristics of information transfer in FOCC QCS. In article the analysis of the energy loss factors in the classical fiber-optic channel is carried out and the additive loss formula is discussed in detail. Then we consider the fiber-optic channel of quantum information transmission with the use of integrated optical devices. The additive formula of optical losses in such a channel is discussed. The features of losses in integrated optical devices are shown. The features of quantum cryptographic system of information transmission are considered. As a result, the model of FOCC QCS taking into account energy losses is presented, which allows competently in theoretical terms and visualize the passage of information through modern quantum cryptographically secure telecommunications while providing control in government structures.
The existing methods of information delivery to the strategic and tactical management of many government agencies are expensive, not always reliable and efficient. Therefore, quantum cryptographic systems (QCS) have been actively developed in recent years. However, there are problems with the use of the QCS associated with the reliability of information transfer. First, the existing fiber-optic communication channels (FOCC) are not designed to transmit single-photon signals, which leads to the complexity of their cryptographic protection. The second is insufficiently methodically developed calculation of energy losses and errors in the evaluation of the characteristics of information transfer in FOCC QCS. In article the analysis of the energy loss factors in the classical fiber-optic channel is carried out and the additive loss formula is discussed in detail. Then we consider the fiber-optic channel of quantum information transmission with the use of integrated optical devices. The additive formula of optical losses in such a channel is discussed. The features of losses in integrated optical devices are shown. The features of quantum cryptographic system of information transmission are considered. As a result, the model of FOCC QCS taking into account energy losses is presented, which allows competently in theoretical terms and visualize the passage of information through modern quantum cryptographically secure telecommunications while providing control in government structures.
The analysis of the performance indicators fiber-optic communication lines (FOCL) using quantum technology based on the architectural concept of NGN (Next Generation Network) and future networks FN (Future Networks) for the construction highly efficient optical telecommunication networks supporting a wide range cryptographic resistance. Threats of unauthorized access, denial of service, loss information, cryptographic methods and algorithms for information protection are considered. Complex criteria of FOCL efficiency using such quantum technologies as network performance using WDM (Wavelength Division Multiplexing) technology, information security characteristics when using quantum cryptography protocols, taking into account resistance to various threats, informative characteristics photon sources are selected. A new approach is proposed for the study and assessment of complex indicators complex optical information protection systems and effective control of a set quantum key distribution systems for fiber-optic communication lines. The functioning of the investigated FOCL using quantum technology based on the principles "Point-to-point" network topology, which allows organizing a quantum information and service channel, is considered. On the basis of the proposed approach, the efficiency quantum key distribution, the capabilities quantum cryptography protocols under the influence of photon number splitting attack (PNS-Photon Number Splitting Attack) and the information entropy of the characteristics of sources of optical photon qubit fluxes are investigated. Analytical expressions are obtained for assessing the complex indicators of the information security system when using quantum key distribution (QKD) for FOCL. On the basis of the new approach, a numerical analysis was carried out and a graphical dependence of the information entropy of the packet on the packet length in qubits was constructed for the given transfer characteristics of the FOCL. It was found that an increase in the limited packet length in bits, which meets the requirements reliability and efficiency of the operation FOCL system, leads to an increase in the value information entropy as a fraction of the packet, at a given bit rate of the network.
With the rapid development of quantum technologies and the growth of complex cyber threats, it is particularly important to create reliable data protection methods that can guarantee the unconditional security of transmitted information.Quantum cryptography works based on stuff like superposition (the ability of particles to be in several states at once), quantum entanglement (how they're connected from a distance), and the fact that it's impossible to exactly copy or change a quantum state.The application of these principles makes it possible to implement quantum key distribution, which ensures the detection of any interference in the communication channel and makes it impossible to intercept information unnoticed.The article analyzes the most well-known quantum cryptographic protocols, in particular BB84 and E91, their architecture, principles of operation, and features of implementation in military conditions.The composition of typical quantum protection systems is considered: light pulse sources, channels for transmitting quantum data, devices for receiving them, information processing modules, and conventional communication channels for control.The issues of compatibility of quantum solutions with the existing infrastructure of military telecommunications systems are considered, and the prospects for hybrid cryptographic models combining quantum and post-quantum approaches are analyzed.A comparative analysis of traditional and quantum cryptography is carried out according to criteria such as reliability, scalability, resistance to attacks, and development potential.The main advantages of using quantum cryptography in the defense sector are highlighted, in particular, ensuring a secure command communication channel, protecting navigation and telemetry systems, and the secure operation of distributed networks in combat conditions.Examples of international developments and research are considered, in particular, the DARPA Quantum Network, the Chinese Micius satellite, and EU projects within the Quantum Flagship initiative.These examples demonstrate the interest of leading countries in introducing quantum technologies into the field of national security.The potential of quantum cryptography as a means of updating and strengthening the cyber defense system in № 8(49) 2025 1018 the defense sector has been identified, taking into account both current challenges and future threats in the digital environment.
Already today, quantum communications networks are being actively deployed and created in Russia and around the world, and standards in the field of quantum technologies are being developed. As part of the roadmap for the development of quantum communications in Russia, the length of quantum networks is more than 7 thousand km, and by 2030 it is planned to be more than 15 thousand km. Quantum communications today are, in fact, a technology of quantum key distribution, which is at the stage of intensive scientific research and development. With regard to backbone quantum networks, the technology of secret key distribution requires new approaches to implementation, since the use of equipment from various vendors and the length of fiber-optic communication lines impose surmountable restrictions on the topology of backbone networks. An important aspect in the design of quantum networks is the calculation of losses in optical communication channels. Attenuations introduced by various passive and active elements are usually calculated individually for each section of the network and ultimately form a comprehensive energy model. The article considers several topologies of backbone quantum networks and presents the calculation of optical losses for fiber-optic communication channels of these topologies. In general, a method for detecting an optical signal in quantum communication networks is presented. The purpose of the article is a comparative analysis of energy models of backbone quantum networks and a presentation of a variant of implementing a section of an urban quantum network. The work describes a generalized principle of operation of a quantum key distribution system both in a two-pass version and in a single-pass configuration. The results of the analysis of the energy model and the calculation of average losses in a quantum channel are presented. In conclusion, we propose for consideration a possible variant of the topology of a quantum network.
Currently, quantum key generation systems are considered as the basis of quantum telecommunications using quantum cryptography. At the same time, concepts are substituted: such a system simply generates the same binary code on two sides of the quantum channel and does not allow data to be transmitted as in the communication channel. In the future, such a key is used by a classical cryptographic system in a conventional communication channel. The low rate of generation of a quantum key requires its accumulation, which deprives this key of authentication – as soon as once it is presented as a file, it can be replaced. Nevertheless, the steady increase in the generation rate makes it possible to use a quantum key for direct secure transmission of information in a quantum channel «bit to bit» with any quantum protocol and physical implementation. The method of such transfer is discussed in this article.
Subject of study. An optical system, composed of transmitting and receiving telescopes, was designed for quantum key distribution, based on the subcarrier wave modulation method, over an atmospheric channel. Aim of study. The aim of the study was to develop an optical system that allowed the use of single-mode fibers as the input and output of the system, ensured the transmission of an ultralow-power optical signal without introducing additional distortion, and implemented a protocol for distributing a quantum key over an atmospheric optical communication channel at a distance of up to 25 m. Method. An experimental setup with an atmospheric quantum communication channel was developed, which showed stable quantum key distribution without interruptions throughout the measurement process. Radiation propagation simulations were also performed to estimate the insertion loss of the optical signal. Main results. Simulations revealed that the optical losses in the quantum key distribution system amounted to approximately 17 dB. The atmospheric communication channel was studied at distances of 5, 10, and 25 m. Considering all optical elements of the system, including the ferrules of the output and input fibers of the quantum key distribution modules, the attenuation of the optical signal was approximately 8, 13, and 18 dB, respectively. Based on the atmospheric optical losses, the quantum key generation rates were of the order of 500, 350, and 190 bits/s with increasing distance and insertion losses. The probability of a quantum error was in the range of 3% to 5%, which was lower than the threshold of 6%, ensuring the legitimacy of the generated key and excluding the possibility of an attack on the communication channel. Practical significance. The compatibility of the developed optical system with single-mode optical fibers allows its integration into the existing infrastructure of data transmission lines without the need for additional optical radiation converters. Owing to the analyzed characteristics of the optical system for distributing a quantum key over an atmospheric communication channel, it can be applied in communication systems based on the Internet of Things, unmanned vehicles, and other moving objects.
The method and the scheme of multichannel quantum system of secure communication for transfer of confidential data on optical fiber are developed. The considered scheme combines quantum key distribution with quantum secure data transmission. Such approach does not give possibility to the eavesdropper to decipher that part of information, which he can receive before the detection. The suggested scheme provides higher security level of transferred confidential information, than known, which use traditional pro-tocols of symmetric enciphering in a combination to quantum key distribution. It is found out that for the transmission protected in such a way on optical fiber the choice of wavelengths of 850 and 1625 nanometers is optimum. It is found out that when using in such systems of the avalanche photo diode FD-115L it is possible to provide a speed of information transfer up to 0,8 Mbps in one channel. For increase in speed of transfer, it is proposed to use two and more channels of transfer.