Quantum protocols for generating shared secret keys represent an effective method of ensuring secure information transmission using quantum communication channels. However, they are limited in scalability due to the physical constraints of quantum channels, which necessitates the use of classical communication channels for exchanging information between participants. This leads to the necessity of developing security threat models and network protection, especially in the case of hybrid networks, where quantum channels are used alongside classical ones. The peculiarity of constructing quantum key distribution protocols is associated with the costliness of implementation and implies the inevitable use of classical communication channels for key distribution. This paper addresses the task of ensuring the security of communication between subscribers not directly connected by quantum channels, through intermediary nodes, and analyzes threats from internal and external adversaries. Special attention is paid to situations where both types of adversaries have information about the processes and protocols in the network. The paper examines widely used key distribution protocols employed in practice. It describes the main security requirements applied to key distribution protocols, and presents the results of an analysis of the compliance of the discussed protocols with these requirements
Quantum protocols for generating shared secret keys represent an effective method of ensuring secure information transmission using quantum communication channels. However, they are limited in scalability due to the physical constraints of quantum channels, which necessitates the use of classical communication channels for exchanging information between participants. This leads to the necessity of developing security threat models and network protection, especially in the case of hybrid networks, where quantum channels are used alongside classical ones. The peculiarity of constructing quantum key distribution protocols is associated with the costliness of implementation and implies the inevitable use of classical communication channels for key distribution. This paper addresses the task of ensuring the security of communication between subscribers not directly connected by quantum channels, through intermediary nodes, and analyzes threats from internal and external adversaries. Special attention is paid to situations where both types of adversaries have information about the processes and protocols in the network. The paper examines widely used key distribution protocols employed in practice. It describes the main security requirements applied to key distribution protocols, and presents the results of an analysis of the compliance of the discussed protocols with these requirements
The main purpose of a quantum key distribution network is to provide secret keys to any users or applications requiring a high level of security, ideally such as to offer the best protection against any computational attack, even of a quantum nature. The keys shared through a point-to-point link between a source and a detector using a quantum key distribution protocol can be proven information-theoretically secure based on the quantum information theory. However, evaluating the security of a quantum key distribution network, especially if it is based on relay nodes, goes far beyond the quantum security of its single quantum links, involving aspects of conventional security for devices and their communication channels. In this contribution, we perform a rigorous threat analysis based on the most recent recommendations and practical network deployment security issues. We show that, at least in the current state of our understanding of quantum cryptography, quantum key distribution networks can only offer computational security and that their supposed resilience to quantum cryptanalysis requires resorting to post-quantum cryptography.
Quantum Security
The deployment of quantum technologies will be reliant on developing platforms that are mass-manufacturable and cost-effective. Quantum key distribution is a protocol that ensures secure communications between various parties within a network using shared secret keys to encrypt the communication channels. However, practical implementations with hybrid systems can leave side channels open, which compromises the security of the network. Semenenko et al. demonstrate a quantum-ready platform based on all the optical components being monolithically integrated on an indium-phosphide photonic chip. With the side channels to information leakage effectively closed and demonstrated secret keys exchanged at rates exceeding 1 kilobit per second over 100 kilometers, such a platform provides a promising solution for the development of secure communication over citywide quantum networks.
Optica 7 , 238 (2020).
Quantum computing poses significant threats to conventional cryptographic techniques such as RSA and AES, motivating the need for quantum secure communication methods. Quantum Key Distribution (QKD) offers information theoretic security based on fundamental quantum principles. This paper presents a simulation-based analysis of well-known QKD protocols, namely BB84, B92, and E91, using the IBM Qiskit framework. Realistic quantum channel effects, including noise, decoherence, and eavesdropping, are modeled to evaluate protocol performance. Key metrics such as error rate, secret key generation, and security characteristics are analyzed and compared. The study highlights practical challenges in QKD implementation, including hardware limitations and channel losses, and discusses insights toward scalable and robust quantum communication systems. The results support the feasibility of QKD as a promising solution for secure communication in the quantum era.
The increasing reliance on optical communication networks for high-speed data transmission has amplified concerns regarding secure information exchange in the era of quantum computing. Classical cryptographic protocols such as RSA and ECC, though widely deployed, are vulnerable to attacks from large-scale quantum computers executing Shor’s algorithm. Quantum Key Distribution (QKD) has emerged as a revolutionary cryptographic paradigm that leverages the principles of quantum mechanics to enable theoretically unbreakable key exchange. This paper investigates the integration of QKD into optical communication networks, focusing on protocol design, implementation challenges, and potential scalability. Through scenario-based evaluation, the study highlights the trade-offs between quantum security and practical deployment constraints such as channel loss, photon detector efficiency, and key generation rates. Results from simulated models demonstrate that while QKD can achieve provable security in metropolitan-area networks, long-distance transmission requires advanced techniques such as quantum repeaters and trusted nodes. This work concludes that QKD offers a promising pathway toward quantum-safe communication but necessitates
The increasing reliance on optical communication networks for high-speed data transmission has amplified concerns regarding secure information exchange in the era of quantum computing. Classical cryptographic protocols such as RSA and ECC, though widely deployed, are vulnerable to attacks from large-scale quantum computers executing Shor�s algorithm. Quantum Key Distribution (QKD) has emerged as a revolutionary cryptographic paradigm that leverages the principles of quantum mechanics to enable theoretically unbreakable key exchange. This paper investigates the integration of QKD into optical communication networks, focusing on protocol design, implementation challenges, and potential scalability. Through scenario-based evaluation, the study highlights the trade-offs between quantum security and practical deployment constraints such as channel loss, photon detector efficiency, and key generation rates. Results from simulated models demonstrate that while QKD can achieve provable security in metropolitan-area networks, long-distance transmission requires advanced techniques such as quantum repeaters and trusted nodes. This work concludes that QKD offers a promising pathway toward quantum-safe communication but necessitates advancements in hardware, standardization, and hybrid cryptographic strategies for widespread adoption.
The work is devoted to the study of the problems of using the technology of quantum distribution of secret keys, namely the problems of using and forming new secret keys, based on the generation of quantum keys and the distribution of new keys in networks of complex topologies. In secure communication systems, information is transmitted over public networks, and thus is available to a potential attacker for carrying out various types of attacks. A potential attacker is able to store encrypted data transmitted over network channels, and attempt to decrypt it later, when technical means and attacks on information protection algorithms will allow, in an acceptable time, to carry out decryption. This is the basic principle of "Store now, decrypt later", which is one of the problems of information protection systems. For block ciphers, there is a parameter - the key load, which limits the amount of information that one key can process using the data protection algorithm. NIST recommends a time frame for using secret keys, calculated in years. In the field of information security, there are more significant restrictions on the key load, related to the number of blocks that can be processed by one key, caused by attacks on block ciphers. With these restrictions, there is a need to regularly change the secret key used, and search for options for generating and delivering keys between two network nodes that organize a secure information transmission channel. Changing the secret key to a new key, independent of the previous one, allows you to protect the transfer of confidential information when the key used is compromised. The technology of creating a quantum computer allows you to effectively attack known algorithms for generating secret keys based on the factorization of large numbers or the complexity of calculating a discrete logarithm. The quantum Shor algorithm [5, 6] allows you to solve these problems in polynomial time, so it is necessary to look for alternative solutions to the problem of regular changes in the network channel of the secret key in a pair of nodes. It is important to take into account the need to ensure the quality of Perfect forward secrecy, when the master key is compromised, all subsequent secret keys must not be compromised. To achieve this property of modern encryption algorithms, there is a periodic update of master keys. To prevent the accumulation of information, to successfully carry out attacks by the attacker and to comply with the load requirement on the secret key, it is necessary to solve the problem of regular changes of the secret, and regular generation/delivery of keys to network nodes. Given the urgent needs that are intensively developing today in the secure and high-speed transmission of information, and no less, the rapid growth of technical capabilities, there is a need to develop options in advance that will ensure the security of information during transmission. Regular change, in geographically dispersed data protection systems, of common secret keys, in the case of ensuring the independence of secret keys, allows successfully solving the task.