IET Quantum Communication最新文献

The emerging technology of reversible circuits offers a potential solution to the synthesis of ultra low-power quantum computing systems. A reversible circuit can be envisaged as a cascade of reversible gates only, such as Toffoli gate, which has two components: k control bits and a target bit (k-CNOT), k ≥ 1. While analysing testability issues in a reversible circuit, the missing-gate fault model is often used for modelling physical defects in k-CNOT gates. A new design-for-testability (DFT) technique is proposed for reversible circuits that deploys bit-swapping using Fredkin reversible gates. It is shown that in an (n × n) circuit implemented with k-CNOT gates, addition of only two extra inputs along with a few Fredkin gates yields easy testability in the circuit. The modified design admits a universal test set of maximum size 2n + 1 that detects all detectable missing gate faults in the original circuit, where n is the number of input/output lines in the circuit. The DFT overhead in terms of quantum cost is much less compared to that of previous approaches. The method is more advantageous for large circuits.

The rapidly developing discipline of quantum computing (QC) employs ideas from quantum physics to improve the performance of traditional computers and other devices. Because of the dramatically improved speed at which it processes data, it can be applied to various issues. QC has many potential applications, but three of the most exciting applications are unstructured search, quantum simulation, and network optimisation. Several existing technologies, such as machine learning, may benefit from its increased speed and precision. In this study, the authors will explore how the principles of QC might be applied to the Internet of Things (IoT) to improve its accuracy, speed, and security. Several approaches exist for achieving this goal, such as network optimisation in IoT using QC, faster computation at IoT endpoints, securing IoT using QC, a quantum sensor for IoT, quantum digital marketing, quantum-secured smart lock etc.

A significant amount of study is being done to review the security promises made for the various ciphers now in use as a result of the development of quantum computing technology. A general attack against symmetric key cryptography primitives that can reduce search costs to the square root is Grover's search algorithm. To implement Grover's algorithm, it is necessary that the target cipher be implemented as a quantum circuit. Despite being relatively new, this area of study has received significant attention from the research community. The authors have estimated the cost of Grover's key search attack against the stream cipher Atom, for the first time, under circuit depth restrictions defined in National Institute of Standards and Technology (NIST) PQC standardisation process. The authors implement the quantum circuit of Atom in QISKIT, (open-source software development kit for working with quantum computers running on IBM Quantum Experience). The results are also compared with other existing literature on LFSR-based stream ciphers, such as Grain-v1, Grain-128-AEAD, and Lizard. The authors also find that, to the best of their knowledge, in the existing literature on estimating the cost of Grover's attack on symmetric ciphers, Atom is the only 128-bit key cipher that meets the threshold of ≈2¹⁷⁰ set by NIST for quantum security of 128-bit key ciphers. The authors also analyse the security of Atom against quantum TMDTO attacks.

In recent times, secure quantum communication in layered networks has emerged as an important area of study. The authors harness the potential offered by multidimensional states in secure quantum communication with only one quantum participant and all the other classical participants. Three protocols are proposed for—(i) entanglement-based layered semi-quantum key distribution, (ii) layered semi-quantum secret sharing, and (iii) integrated layered semi-quantum key distribution and secret sharing to share secret information in arbitrarily layered networks. These protocols integrate the features of semi-quantum communication in layered networks. All three protocols allow for simultaneous distribution of secure information in all the layers of a network, thanks to the employment of multidimensional states. These protocols are presented for a small network of at most five participants and three layers and show the robustness of the same against various eavesdropping strategies. Finally, a detailed procedure is provided for generalisations of the proposed protocols to distribute keys/secrets in any arbitrarily structured quantum network.

The quantum internet is a cutting-edge paradigm that uses the unique characteristics of quantum technology to radically alter communication networks. This new network type is expected to collaborate with 6G networks, creating a synergy that will fundamentally alter how we communicate, engage, and trade information. The improved security, increased speed, and increased network capacity of the quantum internet will lead to the emergence of a broad variety of new applications and services. The current state of quantum technology and its integration with 6G networks are summarised in this study, with an emphasis on the key challenges and untapped possibilities. The main goal is to get knowledge about how the quantum internet might impact communication in the future and alter several economic and societal sectors.

The evolution of quantum computers is considered a serious threat to public-key cryptosystems (e.g. RSA, ECDSA, ECDH, etc.). This is indeed a big concern for security of the Internet and other data communication and storage systems. The reason is that public-key schemes are the basis in the generation of shared symmetric keys that are used to perform data encryption/decryption in communication and data transfer protocols. One possible approach to address this issue is to use Quantum Key Distribution (QKD) (instead of public-key schemes) for the ultra-secure generation of symmetric keys. QKD is a physical layer technology that allows two parties (equipped with optical communication interfaces) to generate secure random keys over a quantum channel that is immune to eavesdropping threats. The keys are then used by symmetric encryption schemes (e.g. AES) to encrypt data over classical channels. This allows us to have data encryption/decryption without needing a public-key scheme. However, due to its inherent characteristics, the implementation of QKD has mostly been considered in particular contexts only (e.g. backhaul networks, point-to-point connections, optical networks, etc.). This indeed limits the utility of QKD technology to only some particular applications while it has the potential to be used in a wide range of used cases. Motivated by this (increasing the usability of QKD technology), in this study, the authors propose a model that enables SDN-based networks to utilise QKD technology and provide QKD security service (i.e., random key generation service) to network applications and security protocols in a practical and efficient way. In the proposed approach, secret keys are generated based on the distribution of quantum entanglement between QKD nodes deployed in the network. The significant characteristic of our proposed model is that it does not rely on quantum repeaters to operate. This also improves the efficiency of the employed QKD mechanisms in terms of the key generation rate.

The emergence of quantum technologies has led to groundbreaking advancements in computing, sensing, secure communications, and simulation of advanced materials with practical applications in every industry sector. The rapid advancement of the quantum technologies ecosystem has made it imperative to assess the maturity of these technologies and their imminent acceleration towards commercial viability. The current status of quantum technologies is presented and the need for a quantum-ready ecosystem is emphasised. Standard Quantum Technology Readiness Levels (QTRLs) are formulated and innovative models and tools are defined to evaluate the readiness of specific quantum technology. In addition to QTRLs, Quantum Commercial Readiness Levels (QCRLs) is introduced to provide a robust framework for evaluating the commercial viability and market readiness of quantum technologies. Furthermore, relevant indicators concerning key stakeholders, including government, industry, and academia are discussed and ethics and protocols implications are described, to deepen the understanding of the readiness for quantum technology and to support the development of a robust and effective quantum ecosystem.

The security of data communications is one of the crucial challenges that our society is facing today. Quantum Key Distribution (QKD) is one of the most prominent methods for guaranteeing ultimate security based on the laws of quantum physics. In this work, the results obtained during the Italian Industry 4.0 Quantum Testbed (II4QuTe) project are reported where the authors realised a QKD testbed securely connecting the Competence Industry Manufacturing 4.0 (CIM4.0) located in Torino and a TIM edge node located 10 km away from the testbed. The edge node accommodates the server providing computation capabilities for managing the real-time data generated by the machines within the CIM4.0 digital factory pilot line, thus gracefully integrating QKD with the MEC (Multi-access Edge Computing) paradigm. The experiment was conducted for more than 69 h, establishing an average key generation rate of 5.125 keys/s (AES-256 keys) and demonstrating the stability of the entire end-to-end encryption system.

Long-distance free space quantum key distribution based on CubeSats can be used to establish global quantum secure communication networks, with potential commercial applications benefitting from the low cost of its design and launch. Detecting single-photon level optical pulses sent from space requires highly accurate and robust timing systems to pick out signals from the noise. For such high-loss applications, we envisage a low-repetition (sub-MHz) beacon laser emitting short (ns) high-peak-power pulses from which interpolated quantum signal arrival windows can be derived. We firstly study theoretically the effects of jitter on the efficiency of gating quantum signals including all important jitter sources, and then experimentally investigated it by changing the clock jitter, and the result shows that the greater jitter will reduce the gating rate of the signal. The experimental interpolation error is tested against loss under laboratory conditions giving results close to our model. We also found that the jitter introduced by the Doppler effect can be ignored with a repetition rate larger than 1 kHz. This model can be directly used for the performance analysis and optimisation of all quantum and non-quantum systems using similar synchronisation schemes over terrestrial free space or fibre.

The evolution of Connected and Autonomous Vehicles (CAVs) promises improvements in our travel experience and the potential to enhance road safety and reduce environmental impact. This will be utilising highly diverse traffic environments that enable several advanced mobility applications. A secure, efficient, reliable, and resilient communications infrastructure is required to support developments in these CAV systems. Next generation of telecommunication networks will seamlessly integrate terrestrial, satellite, and airborne networks into a single wireless system satisfying the requirements of trustworthy future transport systems. Given the increasing importance of CAVs, coupled with their attractiveness as a cyber-attack for threat agents (e.g., disruption of transportation systems by nation states), security is paramount. Future communications systems offer an opportunity to integrate Quantum Key Distribution (QKD) into vehicular environments, protecting against advances in quantum computation that render many of the classical algorithms that underpin Public Key Infrastructure obsolete. This paper proposes a method for the integration of QKD in V2I networks to enable secure data communication. Quantum Key Distribution is used in the end-to-end path of vehicle-to-infrastructure (V2I) networks. Furthermore, an overarching Software-Defined Network, with integrated QKD, is introduced. We have investigated the security performance of QKD in a V2I network over an urban environment.