A multi‐user network that supports both classical and quantum communication is proposed. By relying on optical code‐division multiple access techniques, this system offers simultaneous key exchange between multiple pairs of network users. A lower bound on the secure key generation rate will be derived for decoy‐state quantum key distribution protocols.
A multi‐user network that supports both classical and quantum communication is proposed. By relying on optical code‐division multiple access techniques, this system offers simultaneous key exchange between multiple pairs of network users. A lower bound on the secure key generation rate will be derived for decoy‐state quantum key distribution protocols.
This paper addresses multi-user quantum key distribution networks, in which any two users can mutually exchange a secret key without trusting any other nodes. The same network also supports conventional classical communications by assigning two different wavelength bands to quantum and classical signals. Time and code division multiple access (CDMA) techniques, within a passive star network, are considered. In the case of CDMA, it turns out that the optimal performance is achieved at a unity code weight. A listen-before-send protocol is then proposed to improve secret key generation rates in this case. Finally, a hybrid setup with wavelength routers and passive optical networks, which can support a large number of users, is considered and analyzed.
This paper proposes a possible application of quantum key distribution in multi-user network. In modern networks, variety of multiple access technologies are being used for multi-user access purposes. In this paper, we focus on a type of widely used MAC (Media Access Control) protocol-CSMA/CA, and analyse its use for the quantum key distribution in the network. This work is based on a successful experiment that implemented the quantum key distribution over 200 km by using the decoy-state method. The secret key generation rate as the main indicator of the performance is given, including the relationship between it and the number of stations in the network, and the relationship between the key generation rate and the transmission distance under the multiple access condition as well.
Future communications networks not only should enable massive exchange of classical bits, but also the transmission of quantum bits on which many quantum applications rely. This will be the key to offering quantum technologies in a cost-efficient way, and it should encompass the integration of quantum and classical networks at the core of existing optical communications networks, as well as at the access end of such networks. In this work, we cover a range of proposals that enable such an integration for one of the imminent applications of quantum technologies, i.e., quantum key distribution (QKD), by which users can securely exchange a secret key for their cryptographic needs. This will include using wavelength division multiplexing techniques to send quantum and classical data on the same fiber as well as wireless access for QKD users to passive optical networks. In each case, we explore optimal arrangements to find the best way forward for an amicable coexistence.
This article proposes a potential application of quantum key distribution in multiuser networks. In modern networks, variety of multiple access technologies are used for multiuser access purposes. In this article, we focus on a type of widely used media access control protocol—carrier-sense multiple access (CSMA) and analyze the use of carrier-sense multiple access with collision avoidance (CSMA/CA) for the quantum key distribution in the network. The quantum key generation is based on a successful experiment that implemented the quantum key distribution by using the decoy-state method. The secret key generation rate as the main indicator of the performance is given, including the relationship between it and the number of stations in the network, and the relationship between the key generation rate and the transmission distance under the multiple access condition as well. In addition, a multiple access quantum key distribution with channel detection protocol is also proposed.
Quantum Key Distribution (QKD) and encryption protocols are central to secure user-to-user communication in quantum networks. However, the detection of eavesdropping, security vulnerabilities, and performance degradation at high traffic levels are some of the challenges faced by inefficient multi-user communication. Current approaches do not adequately overcome these challenges. This paper suggests a holistic framework that integrates QKD, classical-quantum multiple access techniques, and advanced security protocols for overcoming these issues. This framework uses the QKD-SCM for communication security across several nodes and makes use of classical-quantum multiple accesses for greater speed and scalability in communication. Security is then further optimized with the MUQQ-ESTMP GHZ based on Multi-User Quantum Protocol, (MUQPQ), where it optimizes queries across several users. Lattice-based cryptography is deployed to protect against quantum computing attacks, and for detecting eavesdropper attacks, the Reverse Reconciliation Algorithm for binary-input additive white Gaussian noise channel (RRA-BIAWGNC) is used. Furthermore, QPQB has been integrated as a searchable symmetric encryption protocol to safeguard the data in cloud storage. The performance of the system has been analyzed with metrics like detection accuracy of eavesdrop attack (97%), communication complexity (95%), effective key rate (590 b/s), communication efficiency (96%), and computational overhead (98%). Simulation has been carried out using ns-3.30.1 and Python. Simulation results indicate a considerable reduction in communication complexity up to 40% and enhanced detection accuracy that surpassed the existing stateof- the-art benchmarks. Through the integration of multiple advanced techniques for security, this research contributes to the development of scalable and quantum communication networks with security.
The ability to generate entangled photon-pairs over a broad wavelength range opens the door to the simultaneous distribution of entanglement to multiple users of a network using a single source and wavelength-division multiplexing technologies. Here we show the design of a metropolitan optical network made of tree-type access networks where entangled photon-pairs are distributed to any pair of users, independently of their location. The resulting network improves the reach, number of users and capabilities of existing proposals. Moreover, it is made up of typical commercial components and uses the existing infrastructure, which allows for moderate deployment costs. Finally, we develop a channel plan and a network design that allow direct optical communications, quantum and classical, between any pair of users. Therefore, multiple quantum information technologies can make use of this network.