Quantum Key Research Articles

Multi-Party Quantum Key Agreement with Four-Qubit Cluster States Immune to Collusive Attack

Multi-Party Quantum Key Agreement with Four-Qubit Cluster States Immune to Collusive Attack

A Multi-Path QKD Algorithm with Multiple Segments

Quantum Key Distribution (QKD) provides unconditional peer-to-peer security based on the principles of quantum physics. By utilizing relay nodes, the security of QKD can be extended over longer distances. However, the introduction of relay nodes brings both security and communication success rates issues. To tackle those issues we propose an enhanced multi-path scheme. The key features of our proposal are as follows: 1. By taking the reliability of relay nodes as one of the algorithm inputs,making the scheme more suitable for partially trusted QKD (PTQKD) networks. 2. By using Multi-Segment Multi-Path approach increases the difficulty for attackers to obtain complete key information and improves the security of PTQKD. 3. The adaptive routing algorithm generates a sufficient number of diverse paths based on node contribution rate, key freshness, and reliability. We conducted a theoretical analysis of the algorithm,and simulation results on PTQKD demonstrate that our method outperforms traditional QKD methods in terms of security and transmission success rate. This advancement has the potential to enhance the adoption of QKD networks.

Low-complexity adaptive reconciliation protocol for continuous-variable quantum key distribution

In continuous-variable quantum key distribution systems, reconciliation is a crucial step that significantly affects the secret key rate (SKR). The rateless protocol based on Raptor codes can achieve high reconciliation efficiency at low signal-to-noise ratios (SNRs). However, the high complexity of low-density parity-check (LDPC) codes used for the precoding in Raptor codes limits the speed of reconciliation. In this paper, we propose an adaptive reconciliation protocol by modifying Raptor codes. The length of random binary sequences is increased because we remove the LDPC precoding that adds redundancy. The modified Raptor codes reduce the complexity of encoding with better performance. The proposed protocol gives a reconciliation efficiency higher than 98.1% in the SNR below −20 dB and maintains a certain SKR in long-distance transmission.

A new quantum key distribution resource allocation and routing optimization scheme

Quantum key distribution (QKD) is a technology that can resist the threat of quantum computers to existing conventional cryptographic protocols. However, due to the stringent requirements of the quantum key generation environment, the generated quantum keys are considered valuable, and the slow key generation rate conflicts with the high-speed data transmission in traditional optical networks. In this paper, for the QKD network with a trusted relay, which is mainly based on point-to-point quantum keys and has complex changes in network resources, we aim to allocate resources reasonably for data packet distribution. Firstly, we formulate a linear programming constraint model for the key resource allocation (KRA) problem based on the time-slot scheduling. Secondly, we propose a new scheduling scheme based on the graded key security requirements (GKSR) and a new micro-log key storage algorithm for effective storage and management of key resources. Finally, we propose a key resource consumption (KRC) routing optimization algorithm to properly allocate time slots, routes, and key resources. Simulation results show that the proposed scheme significantly improves the key distribution success rate and key resource utilization rate, among others.

Application solutions of highway freight information systems based on quantum communication.

To improve the security of data transmission in the highway freight information system, this study is an application plan for the highway freight information system based on quantum communication. This solution is based on quantum communication technology to encrypt and transmit key sensitive data[1]; it realizes unified management of quantum keys through the quantum key cloud terminal and provides key services for the highway freight information system; it realizes access to the system through the quantum key cloud service platform. The secure use of mobile terminal quantum keys improves the overall security of the road freight information system. This scheme uses the quantum encryption key generated only once, effectively protecting the entire system's security. The quantum key management server and quantum key cloud platform defined in this plan manage terminals and quantum keys respectively, and jointly produce and distribute quantum keys with the help of other hardware facilities and software to provide secure transmission of key information.

Effect on a QKD Chain Going Through a Generic Pauli Channel Together with a Correction Based on the 3-qubit Code

Quantum cryptography is an emergent area in quantum technologies to set secure communication. BB84 protocol is a procedure to exchange a secure key to encode communication in the form of a chain of quantum bits. In this work, we model the non-ideal transmission of such a key through a parametric family of noisy channels: Pauli channels (including Bit-flipping and Dephasing noises). Assuming that Quantum Key Distribution is performed under such protocol, we analyse the fidelity of the transmission and the probability distribution for the imperfect outcomes. The analysis also includes the application of the quantum error correction algorithm: the 3-qubit code. Finally, we add the presence of an eavesdropper getting his conditional success rate to become unnoticed. The agreement in the basis selection between the transmitter and receiver is assumed as under a tentative reconciliation procedure. Outcomes show just positive effects on the transmission between sender and receiver, but a mild improvement for the success probability for the eavesdropper.

Quantum Key Distribution Shared Protocol Using Teleportation and Delayed Measurement

With the rise of quantum computers, cryptographic protocols are being required to set secure communications. In the current study, a 3-party Quantum Key Distribution protocol is proposed to ensure safe communication considering ideas from BB84 and GR10 protocols against eavesdropping by using a parameterized partially entangled resource. The protocol is built so that the sender is the only one knowing the code key and the message encryption is made ongoing. Delayed measurements are applied just at the end of the protocol to decode the message effectively. The parameter of the entangled resource is used as a double control for the exchange rate of classical communications involved in the procedure. Finally, a security analysis is made, where multiple coordinated attacks could be a threat to this protocol.

Secure method of communication using Quantum Key Distribution

Secure communication plays a vital role now-a-days. Modern-day secure communication is made possible via cryptography. Modern cryptographic algorithms are based on the process of factoring large integers into their primes, as they are intractable. But the cryptography nowadays is vulnerable to technological advances in computing power like quantum computing and evolution in math to quickly reverse one-way functions like factorization of large integers. Incorporating quantum physics concepts into cryptography is the answer, which results in an assessment of quantum cryptography. A unique type of cryptography known as quantum cryptography makes advantage of quantum mechanics to provide complete protection against the transmitted message. Quantum Key Distribution (QKD), a random binary key distribution used in quantum cryptography, enables communication participants to recognize unauthorized listeners. Quantum Key Distribution (QKD) is likely the most advanced quantum technology currently accessible with full stack systems already in use. This projects goal is to develop secure and encrypted communication between the parties with the help of a web application using the BB84 protocol.

Service for Deploying Digital Twins of QKD Networks

Quantum technologies promise major advances in different areas. From computation to sensing or telecommunications, quantum implementations could bring significant improvements to these fields, arousing the interest of researchers, companies, and governments. In particular, the deployment of Quantum Key Distribution (QKD) networks, which enable the secure dissemination of cryptographic keys to remote application entities following Quantum Mechanics Principles, appears to be one of the most attractive and relevant use cases. Quantum devices and equipment are still in a development phase, making their availability low and their price high, hindering the deployment of physical QKD networks and, therefore, the research and experimentation activities related to this field. In this context, this paper focuses on providing research stakeholders with an open-access testbed where it is feasible to emulate the deployment of QKD networks, thus enabling the execution of experiments and trials, where even potential network attacks can be analyzed, without the quantum physical equipment requirement, nor compromising the integrity of an already built QKD network. The designed solution allows users to automatically deploy, configure, and run a digital twin environment of a QKD network, offering cost-effectiveness and great flexibility in the study of the integration of quantum communications in the current network infrastructures. This solution is aligned with the European Telecommunications Standard Institute (ETSI) standardized application interface for QKD, and is built upon open-source technologies. The feasibility of this solution has been validated throughout several functional trials carried out in the 5G Telefónica Open Network Innovation Centre (5TONIC), verifying the service performance in terms of speed and discarded qubits when generating the quantum keys.

A Novel Continuous-Variable Quantum Key Distribution Scheme Based on Multi-Dimensional Multiplexing Technology

Dual-polarization division multiplexing (DPDM) is considered to be a potential method to boost the secure key rate (SKR) of the continuous-variable quantum key distribution (CV-QKD) system. In this article, we propose a pilot alternately assisted local local oscillator (LLO) CV-QKD scheme based on multi-dimensional multiplexing, where time division multiplexing and frequency division multiplexing are combined with dual-polarization multiplexing techniques to dramatically isolate the quantum signal from the pilot tone. We establish a general excess noise model for the LLO CV-QKD system to analyze the influence mechanism of various disturbances (e.g., time-domain diffusion, frequency-domain modulation residual, and polarization perturbation) on the key parameters, such as the channel transmittance and excess noise. Specifically, the photon leakage noise from the reference path to the quantum path and that between quantum signals with two different polarization paths are simultaneously analyzed in the dual-polarization LLO CV-QKD scheme for the first time. Furthermore, a series of simulations are established to verify the performance of the proposed scheme. The results show that the maximal isolation degree achieves 84.0 dB~90.4 dB, and the crosstalk between pilot tones and quantum signals can be suppressed to a very small range. By optimizing the system parameters (e.g., modulation variance and repetition frequency), the SKR with 12.801 Mbps@25 km is achieved under the infinite polarization extinction ratio (PER) and 30 dB residual ratio of the frequency modulation in the nanosecond-level pulse width. Moreover, the performance of the proposed DPDM CV-QKD scheme under relatively harsh conditions is simulated; the results show that the SKR with 1.02 Mbps@25 km is achieved under a relatively low PER of 17 dB with the nanosecond-level pulse width and 20 dB residual ratio of the frequency modulation. Our work lays an important theoretical foundation for the practical DPDM LLO CV-QKD system.

Retracted: Cryptanalysis and Improvements on Quantum Key Agreement Protocol Based on Quantum Search Algorithm

Retracted: Cryptanalysis and Improvements on Quantum Key Agreement Protocol Based on Quantum Search Algorithm

Efficient Integration of Rate-Adaptive Reconciliation with Syndrome-Based Error Estimation and Subblock Confirmation for Quantum Key Distribution.

An effective post-processing algorithm is essential for achieving high rates of secret key generation in quantum key distribution. This work introduces an approach to quantum key distribution post-processing by integrating the three main steps into a unified procedure: syndrome-based error estimation, rate-adaptive reconciliation, and subblock confirmation. The proposed scheme employs low-density parity-check codes to estimate the quantum bit error rate using the syndrome information, and to optimize the channel coding rates based on the Slepian-Wolf coding scheme for the rate-adaptive method. Additionally, this scheme incorporates polynomial-based hash verification in the subblock confirmation process. The numerical results show that the syndrome-based estimation significantly enhances the accuracy and consistency of the estimated quantum bit error rate, enabling effective code rate optimization for rate-adaptive reconciliation. The unified approach, which integrates rate-adaptive reconciliation with syndrome-based estimation and subblock confirmation, exhibits superior efficiency, minimizes practical information leakage, reduces communication rounds, and guarantees convergence to the identical key. Furthermore, the simulations indicate that the secret key throughput of this approach achieves the theoretical limit in the context of a BB84 quantum key distribution system.

A Secure Method of Communication Through BB84 Protocol in Quantum Key Distribution

Security awareness is one of the most pressing topics in today's globe. The idea of cryptography is introduced when the subject is information security. Conventional cryptography-based security techniques rely on the presumption that keys are shared before secure connections. The most crucial factor to consider when integrating cryptographic operations into account when integrating cryptographic operations in with any system is the safe key management strategy required for sending and transferring a secret key between two entities The systems will be vulnerable to bugs and possibly fatal external assaults if the fundamental management methods are poor A method for securely encrypting data sent between parties is quantum cryptography. and spotting eavesdroppers trying to overhear the conversation. Quantum cryptography may be the solution to these issues a quantum cryptography application, Quantum Key Distribution (QKD), refers to the production of a cryptographic key with unconditional security assured by physical rules. Quantum cryptography is a kind of encryption. We examine the quantum key exchange protocol (BB84 protocol) in this study and the way that it significantly improves data transfer security when compared to standard encryption techniques. The main objective of quantum cryptography is to offer a trustworthy way to provide a secure method of communication between the intended peers only and to detect the Eavesdropper presence.

Quantum Key Distribution with Post-Processing Driven by Physical Unclonable Functions

Quantum key distribution protocols allow two honest distant parties to establish a common truly random secret key in the presence of powerful adversaries, provided that the two users share a short secret key beforehand. This pre-shared secret key is used mainly for authentication purposes in the post-processing of classical data that have been obtained during the quantum communication stage, and it prevents a man-in-the-middle attack. The necessity of a pre-shared key is usually considered to be the main drawback of quantum key distribution protocols, and it becomes even stronger for large networks involving more than two users. Here, we discuss the conditions under which physical unclonable functions can be integrated in currently available quantum key distribution systems in order to facilitate the generation and the distribution of the necessary pre-shared key with the smallest possible cost in the security of the systems. Moreover, the integration of physical unclonable functions in quantum key distribution networks allows for real-time authentication of the devices that are connected to the network.

Система мониторинга безопасности технологических операций на основе квантового блокчейна

Quantum key generation systems are usually considered only as the basis of quantum telecommunications using quantum cryptography. Currently, the issues of safety of the techno genic environment of human existence in the conditions of the fourth industrial revolution are being implemented within the framework of the Safenet project of the National Technology Initiative of the Russian Federation. One of the main areas of work within the framework of this project is the development of software and hardware based on the use of quantum keys and block chain technology. Development testing is based on the Safenet cyber polygon under the auspices of the Government of St. Petersburg at the Ingria ETC site. One of such developments – a system for monitoring technological security for ICS based on a quantum block chain is considered.

UAV-Assisted Quantum Key Distribution for Secure Communications with Resource Limited Devices

UAV-Assisted Quantum Key Distribution for Secure Communications with Resource Limited Devices

Development of a Hybrid Quantum Key Distribution Concept for Multi-User Networks

Development of a Hybrid Quantum Key Distribution Concept for Multi-User Networks

Probabilistic Amplitude Shaping for Continuous-Variable Quantum Key Distribution With Discrete Modulation Over a Wiretap Channel

Probabilistic Amplitude Shaping for Continuous-Variable Quantum Key Distribution With Discrete Modulation Over a Wiretap Channel

Research on Vehicle-to-cloud Communication Based on Lightweight Authentication and Extended Quantum Key Distribution

Research on Vehicle-to-cloud Communication Based on Lightweight Authentication and Extended Quantum Key Distribution

Efficient Image Encryption via 2D Logistic Chaos Mapping: Strengthening Security with Pixel-Level Dynamics

This study presents an innovative image encryption algorithm anchored on the two-dimensional Logistic chaotic system, designed to address the limitations of traditional methods in terms of speed and security. The algorithm employs pixel shifting and scrambling, coupled with a segmented grayscale value substitution, to achieve a high level of security with strong key sensitivity and robust resistance to both differential and statistical attacks. Experimental validation demonstrates its superiority with fast encryption speeds, as evidenced by an encryption time of 0.2136 seconds for a 256×256 color image, and an entropy close to its ideal value, indicating excellent randomness. This method also exhibits high performance in resisting differential attacks, with Number of Pixels Change Rate (NPCR) and the Unified Average Changing Intensity (UACI) values nearing their optimal expected values. The integration of Quantum Key Distribution (QKD) is suggested for future work to enhance security against quantum computing threats, solidifying the algorithm’s potential as a leading solution for the image encryption.