Quantum cryptography protocols make it possible not only to ensure the protection of data transmitted in a communication channel from unauthorized access by intruders, but also to detect the existence of any attempted interception. This scientific direction is currently relevant, since it is related to the problem of security and data protection in current information and communication networks. The article is devoted to quantum cryptography; it describes the development of quantum protocols as quantum key distribution systems. Grounded on the laws of quantum mechanics, the elaboration of modifications of secure data transfer protocols is shown. The authors considered the best-known protocol to be BB84 of quantum key distribution; a more modern modification of this protocol is BB84 Info-Z. Comparative analysis of these has also been carried out. It has been established that the BB84-Info-Z quantum protocol works more efficiently than BB84 since its lower error threshold allows the interceptor to obtain much less information about the secret key. The authors put forward a new idea to improve the BB84 protocol (which has been quite outdated for almost 40 years), due to the increase in modern requirements for quantum cryptography protocols. The modification is called CSLOE-2022. It enables significant intensification of cryptographic strength and the entanglement degree of the interceptor (cryptanalyst), which greatly complicates the very possibility of intercepting information. The ultimate goal of the CSLOE-2022 modification is to complicate the eavesdropping process so much that it can be considered completely useless for an attacker in terms of wasting time and resources. The modification allows exceeding the known speed limit of key generation without repeaters since it uses two sources, the phases of which, in addition to the hundreds of kilometers of fiber between them, are very difficult to stabilize. Comparison of the protocols by working distance showed that for BB84, this distance does not exceed 70 km; for BB84-Info-Z it is similar, at no more than 70 km, and the modification of CSLOE-2022 proposed by the authors theoretically allows increasing the working distance of the quantum protocol to 511 km (7.3 times).
Quantum cryptography protocols make it possible not only to ensure the protection of data transmitted in a communication channel from unauthorized access by intruders, but also to detect the existence of any attempted interception. This scientific direction is currently relevant, since it is related to the problem of security and data protection in current information and communication networks. The article is devoted to quantum cryptography; it describes the development of quantum protocols as quantum key distribution systems. Grounded on the laws of quantum mechanics, the elaboration of modifications of secure data transfer protocols is shown. The authors considered the best-known protocol to be BB84 of quantum key distribution; a more modern modification of this protocol is BB84 Info-Z. Comparative analysis of these has also been carried out. It has been established that the BB84-Info-Z quantum protocol works more efficiently than BB84 since its lower error threshold allows the interceptor to obtain much less information about the secret key. The authors put forward a new idea to improve the BB84 protocol (which has been quite outdated for almost 40 years), due to the increase in modern requirements for quantum cryptography protocols. The modification is called CSLOE-2022. It enables significant intensification of cryptographic strength and the entanglement degree of the interceptor (cryptanalyst), which greatly complicates the very possibility of intercepting information. The ultimate goal of the CSLOE-2022 modification is to complicate the eavesdropping process so much that it can be considered completely useless for an attacker in terms of wasting time and resources. The modification allows exceeding the known speed limit of key generation without repeaters since it uses two sources, the phases of which, in addition to the hundreds of kilometers of fiber between them, are very difficult to stabilize. Comparison of the protocols by working distance showed that for BB84, this distance does not exceed 70 km; for BB84-Info-Z it is similar, at no more than 70 km, and the modification of CSLOE-2022 proposed by the authors theoretically allows increasing the working distance of the quantum protocol to 511 km (7.3 times).
Cryptography is being introduced to secure data. Through Classical Cryptographic technique, we can encrypt our data and secure secret key also. But classical cryptography is based on mathematical techniques where reversing one-way function is possible with sufficient computing power and time. So, Quantum Cryptography is introduced to overcome those drawbacks of traditional classical cryptography. It is based on the values of quantum mechanics and photon. Scientists and researchers have brought up a new key distribution protocol based on Quantum Cryptography is called Quantum Key Distribution (QKD) Protocol. The first QKD protocol BB84 was introduced by Charles Bennett and Gilles Brassard in 1984. After that several QKD protocols have been created. In this paper we have improved BB84 Protocol by removing the drawbacks of the existing algorithm towards Eavesdropping which may not be detected or disclosing large portion of secret key. Steps of the existing BB84 algorithm along with the modified one is described in detail with example and pseudo code. Limitations of BB84 and comparative study of both the existing and the improved one based on their security has been made and described in this current work.
Quantum Cryptography is a novel approach to make the information and network world more secure. Unlike classical cryptography, quantum cryptography ensures the security of communication because it is based on the laws of Quantum Mechanics; a branch of physics that deals with the fundamental behavior of matter and their energies to the levels of subatomic particles. These particles and their intrinsic properties such as photon polarization and entanglement allow us to develop an unbreakable system of cryptographic information. Conventionally, the security has been primarily concerned with the secured distribution of secret key carried over an insecure channel. However, in Quantum Cryptographic systems the transmission of secret key is done using aforementioned laws of nature through a secured quantum channel highly susceptible to intrusion detection. Consequently, the Quantum Key Distribution (QKD), in conjunction with protocols such as BB84 protocol has emerged as an ultimate modern secured communication system. This article concentrates on briefly reviewing quantum cryptography, some recent developments and reports of its vulnerabilities.
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.
Currently, theoretical and experimental work in the field of quantum cryptography is being carried out in many research centers around the world. Over the past two decades since the start of active research, many quantum cryptographic protocols have been proposed, a significant number of laboratory experiments have been performed on their practical implementation, important work has been done to prove the resistance of the proposed protocols to certain types of attacks, and the first commercial quantum key distribution systems have been developed. However, there are still many tasks and problems in the field of quantum cryptography, the solution of which is of great scientific and technical importance. So, in particular, such a promising direction as quantum protocols for direct secure communication requires further development, allowing, under certain conditions, to transfer secret information without encryption, both between two and between a large number of users. Currently, such protocols have been developed using two-and three-particle entangled states, but there are almost no similar protocols with entangled states of a larger number of qubits that do not require large quantum memory for their implementation and, at the same time, have a large information capacity. Therefore, the development of new quantum direct secure communication protocols with increased information capacity, the analysis of their resistance to attacks, as well as the determination of the best protocols according to the criteria of resistance and information capacity.
Data transmission has always been vulnerable to eavesdropping.Conventional cryptography has provided security in data communication, however it has some limitations when dealing with passive eavesdropping.Recently, the quantum mechanics has made a remarkable entry in the field of data communication.Now, it is possible to construct cryptographic communication systems which detect unauthorized eavesdropping and guarantee its prevention.Several protocols have been devised to implement such systems e.g., BB84, B92 and EPR.The famous BB84 protocol describes quantum encryption in terms of polarization states of a photon.The secret information is t ransmitted via secure quantum channel followed by a public conversation for verification and reconciliation.The B92 protocol is an extension of BB84 which shows how photons with non-orthogonal states can be used to distribute a secret key.The EPR protocol utilizes an entangled photon pair for encryption-one photon from this pair is transmitted towards the destination while keeping the other at the source; the destination photon describes the state of the source photon, failing to which confirms the intrusion.This paper presents a study of these protocols and a review on the recent developments in the field of secure quantum transmission.
Nowadays security in communication is increasingly important to the network communication because many categories of data are required restriction on authorization of access, modify, delete and insert.Quantum cryptography is one of the solutions that use property of polarization to ensure that transmitted data is not tampered.The research paper provides the mechanism that enhances the data security in quantum cryptography during exchange of information.In first phase detailed explanation of Quantum key distribution's BB84 protocol is given.BB84 protocol is used as the basis for the mechanism.In next phase the proposed mechanism is explained.The proposed mechanism combines BB84 protocol at two levels, from sender to receiver and then from receiver to sender.Moreover, a logic circuit is used to combine the bits hence to reduce the probability of eavesdropping.The key obtained can be used to exchange the information securely further it can help in encryption and decryption of crucial data.Double level BB84 mechanism will help in information reconciliation as well as privacy amplification.In future the proposed mechanism will be very beneficial where unconditional security is required during key and other secret information exchange