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The ability to control the optical properties of a material with an electric field has led to optical memory devices, communication systems, optical signal processing, or quantum cryptography. Understanding electro-optic effects, especially in thin films, would improve the efficiency of these applications. In particular, the influence of epitaxial strains is of prime importance. In addition, the active control of these effects would be of great interest to tailor the material to the desired performance. Here, we demonstrate through first-principle calculations that the linear electro-optic response (Pockels effect) of two silicon-compatible ferroelectrics is stable with respect to bi-axial strain and that the electro-optic response can be strongly enhanced through the electrical control of the polarization. We attribute the former to the lack of optical phonon softening and a weak elasto-optic response and the latter to the externally induced softening of a phonon of symmetry A 1. Our results are readily applicable to other polar materials and show that the electro-optic effect can be efficiently engineered to meet the performance criteria of future technologies. [ABSTRACT FROM AUTHOR]

Shor's factorization algorithm (SFA) aims at finding the non-trivial factor of a given composite number, but the algorithm does not always work. In some cases, it has to call back to the beginning of the algorithm to make recalculation. After the analysis of the principle of SFA and the characteristics of RSA public-key cryptography with a series of data calculations, it can be concluded that the random value selected by the algorithm is closely related to whether the obtained period is effective. Therefore, a new optimized scheme is proposed to tackle with this defect from two perspectives: (a) When the a value is a perfect square, the algorithm can be completed with an odd cycle r. (b) When the period r obtained by the randomly selected a value is a multiple of 3 , the algorithm can be completed by modifying the decomposition method to relax the requirements for the period without affecting the complexity of the algorithm. Due to the limitations of hardware in applying the quantum algorithms, the classical algorithm is applied to simulate quantum algorithms to test the success rate of decomposition of some composite numbers. The result indicates the effectiveness of the improved algorithm, which significantly reduces the probability of repeated operations to save the quantum circuit resources. [ABSTRACT FROM AUTHOR]

This paper presents an innovative entanglement-based protocol to address the Dining Cryptographers problem, utilizing maximally entangled |GHZn⟩ tuples as its core. This protocol aims to provide scalability in terms of both the number of cryptographers n and the amount of anonymous information conveyed, represented by the number of qubits m within each quantum register. The protocol supports an arbitrary number of cryptographers n, enabling scalability in both participant count and the volume of anonymous information transmitted. While the original Dining Cryptographers problem focused on a single bit of information—whether a cryptographer paid for dinner—the proposed protocol allows m, the number of qubits in each register, to be any arbitrarily large positive integer. This flexibility allows the transmission of additional information, such as the cost of the dinner or the timing of the arrangement. Another noteworthy aspect of the introduced protocol is its versatility in accommodating both localized and distributed versions of the Dining Cryptographers problem. The localized scenario involves all cryptographers gathering physically at the same location, such as a local restaurant, simultaneously. In contrast, the distributed scenario accommodates cryptographers situated in different places, engaging in a virtual dinner at the same time. Finally, in terms of implementation, the protocol accomplishes uniformity by requiring that all cryptographers utilize identical private quantum circuits. This design establishes a completely modular quantum system where all modules are identical. Furthermore, each private quantum circuit exclusively employs the widely used Hadamard and CNOT quantum gates, facilitating straightforward implementation on contemporary quantum computers.

Abstract 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.

Abstract 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.

Abstract 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.

Abstract 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.

Abstract 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.

Abstract 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.

Large number factorization is not only the most critical entry point for Rivest–Shamir–Adleman (RSA) security analysis, but also the most direct means of attacking the asymmetric encryption algorithm RSA. In this paper, the factorization methods of large numbers are summarized and analysed: classical integer factoring algorithms, Shor's circuit model algorithm, quantum adiabatic methods (integer factorization based on a quantum nuclear magnetic resonance (NMR) platform and D-Wave quantum annealing), and hybrid quantum-classical computing. Finally, the feasibility of integer factorization based on quantum adiabatics is discussed. In this paper, quantum annealing is regarded as a quantum attack method that is completely different from the famous Shor algorithm, and the potential of D-Wave factorization of large numbers to crack RSA cryptography is verified, which provides a new idea for a quantum attack on RSA public key cryptography. [ABSTRACT FROM AUTHOR]

The Internet of Things and Quantum Computing raise concerns, as Quantum IoT defines security that exploits quantum security management in IoT. The security of IoT is a significant concern for ensuring secure communications that must be appropriately protected to address key distribution challenges and ensure high security during data transmission. Therefore, in the critical context of IoT environments, secure data aggregation can provide access privileges for accessing network services. "Most data aggregation schemes achieve high computational efficiency; however, the cryptography mechanism faces challenges in finding a solution for the expected security desecration, especially with the advent of quantum computers utilizing public-key cryptosystems despite these limitations. In this paper, the Secure Data Aggregation using Quantum Key Management scheme, named SDA-QKM, employs public-key encryption to enhance the security level of data aggregation. The proposed system introduces traceability and stability checks for the keys to detect adversaries during the data aggregation process, providing efficient security and reducing authentication costs. Here the performance has been evaluated by comparing it with existing competing schemes in terms of data aggregation. The results demonstrate that SDA-QKM offers a robust security analysis against various threats, protecting privacy, authentication, and computation efficiency at a lower computational cost and communication overhead than existing systems. [ABSTRACT FROM AUTHOR]

In this paper, we proposed an efficient single-state three-party quantum key agreement (QKA) protocol. We proved that the protocol can resist potential outside attacks and inside attacks, and we generalized the efficient single-state three-party QKA scheme into the case of the N-party by substituting N-particle entangled state for three-particle entangled state as the resource quantum states. Compared with the previous QKA protocols, our scheme contains the good features of previous schemes, i.e., using one kind of maximally entangled states as the quantum resource, no requirements for pre-shared key between different participants, and no requirements for executing any unitary operations or quantum entanglement swapping. Furthermore, our scheme has significant improvements in terms of the times of quantum states transmission, the consumed qubits, and the qubit efficiency. In particular, as the number of participants increases, the number of qubits required by our scheme increases linearly rather than exponentially. [ABSTRACT FROM AUTHOR]

Secure quantum multiparty computation is an important field of quantum computing. Many of the preceding aggregation approaches are (n, n) threshold-dependent strategies, where n denotes the total number of participants. The previous aggregating techniques cannot aggregate the secret effectively if one participant is dishonest. This paper presents a quantum technique for secure aggregation. This technique is (t, n) threshold-dependent scheme, where t is the threshold number of participants. We used the properties of quantum mechanics to provide security in quantum aggregation. This technique can compute the aggregation of secrets securely with less computation and communication costs. The proposed aggregation technique is efficient and secure as compared to existing techniques. The simulation results of the proposed technique ensure correctness and practicality. [ABSTRACT FROM AUTHOR]

In the last two decades, structured light patterns with orbital angular momentum (OAM) have been extensively utilized in quantum cryptography or quantum key distribution (QKD), which is generally considered an unconditionally secure method of a secret key transmission between two distant communicating entities. High-dimensional encoding of quantum bits in quantum key distribution improves the security and information-carrying capability of a quantum signal. However, the free space optical channel significantly degrades the efficiency of such communication due to the aberration of OAM states under atmospheric turbulence. This paper focuses on analyzing the impact of atmospheric turbulence on QKD error-rates. These aid in analyzing the security of such communication over the quantum channel in the presence of an intruder (man-in-the-middle). Our results showed that the turbulence under normal conditions does not significantly affect the successful transmission of secret quantum bits between sender and receiver. Furthermore, our results show a unique pattern of variation in the quantum bit error rate, index transmission error rate and efficiency that helps to clearly detect the presence of an intruder as a result of medium-level turbulence. [ABSTRACT FROM AUTHOR]

The aim of device-independent quantum key distribution (DIQKD) is to study protocols that allow the generation of a secret shared key between two parties under minimal assumptions on the devices that produce the key. These devices are merely modeled as black boxes and mathematically described as conditional probability distributions. A major obstacle in the analysis of DIQKD protocols is the huge space of possible black box behaviors. De Finetti theorems can help to overcome this problem by reducing the analysis to black boxes that have an iid structure. Here we show two new de Finetti theorems that relate conditional probability distributions in the quantum set to de Finetti distributions (convex combinations of iid distributions) that are themselves in the quantum set. We also show how one of these de Finetti theorems can be used to enforce some restrictions onto the attacker of a DIQKD protocol. Finally we observe that some desirable strengthenings of this restriction, for instance to collective attacks only, are not straightforwardly possible. [ABSTRACT FROM AUTHOR]

Edge computing (EC) aided Internet of Things (IoT) based applications require real-time processing as well as high-volume data-intensive services as 5G networks evolve. It is difficult to fit IoT services into available edge nodes (ENs) while maintaining performance measures on quality of service (QoS) because of the heterogeneity, restricted resources, and changing resource demand of IoT applications. This study aims to examine a quantum healthcare model that is built on mobile edge computing networks linked with smart IoT. Serverless computing with edge computing may handle quick or small-scale tasks effectively at edge devices, lowering latency. Moreover, serverless edge computing now faces significant hurdles from security and processing performance. In order to provide trustworthy and secure edge serverless services, it is possible to use blockchain technology to boost processing speed and quantum computing to enhance security. In terms of decreasing dependency on IoT cloud analytics or storage facilities, the test results were promising. Lastly, we cover the many aspects that impact the viability of integrating an edge-IoT ecosystem, such as design, capability requirements, functional challenges, and selection criteria. [ABSTRACT FROM AUTHOR]

This study identifies a participant attack vulnerability in Li et al.'s SQPC protocol. The participant attack allows a malicious participant, Bob, to obtain the participant Alice's secret information by intercepting and measuring photons sent to Alice, and later decrypting Alice's encrypted comparison result. An improved SQPC protocol is proposed to address this problem. The key enhancement is introducing a mutual eavesdropping check requiring the third party and participants to verify they obtain the same photon measurement results. This enables detecting participant attacks like the one identified. The SQPC protocol proposed in this study not only withstands attacks from internal participants but also achieves quantum efficiency almost equivalent to Li et al.'s SQPC protocol. Thus, this study presents a more secure SQPC protocol without compromising quantum efficiency. [ABSTRACT FROM AUTHOR]

This paper puts forward a novel quantum dialogue (QD) protocol without information leakage based on single photons in both polarization and spatial-mode degrees of freedom. In this protocol, the receiver sends his private message to the sender in the way of quantum secure direct communication; and the receiver decodes out the private message of the sender with the help of auxiliary single photons in two degrees of freedom, double controlled-not (CNOT) operations and an auxiliary classical bit sequence sent from the sender. As a result, no information leakage takes place. Moreover, this protocol is proven to defeat the intercept-resend attack, the measure-resend attack, the entangle-measure attack and the Trojan horse attack from an outside eavesdropper. This protocol only employs single photons in two degrees of freedom as quantum resource and needs single-photon measurements. The qubit efficiency of this protocol is as high as 66.7%. [ABSTRACT FROM AUTHOR]

Quantum network allows communication among more than two users with quantum teleportation and high quantum fidelity enabled by non-classical resources. As one of the most versatile architectures, all users are connected mediated by the central station in the star topology network, leading to the realization of the information interconnection and interoperability. In this work, we experimentally demonstrate a 4-branch continuous variable (CV) quantum teleportation network with star topology by employing entangled sideband modes from one squeezed state of light. Here, multiple pairs of entangled sideband modes are distributed on demand to central station and four nodes, respectively. Each node linked to the network has its own communication channel with the central station, where the deterministic CV quantum teleportation protocol is implemented with the fidelities above 0.830. [ABSTRACT FROM AUTHOR]

Quantum photonic platforms have proven to be essential in realizing fundamentally secure quantum transfer of information, with commercially ready systems already deployed in municipal and terrestrial links. The drive toward higher bit rates and robustness to eavesdropping and noisy channels has focused attention on moving from the present two-dimensional quantum states of polarization, to harnessing all of light's degrees of freedom for multi-dimensional quantum coding with structured photons. In this Perspective, we outline the present state-of-the-art in achieving this control with spatial modes of light, both as single photon and entangled states, highlight the open challenges that remain, and consider the roadmap that might see its full potential realized. [ABSTRACT FROM AUTHOR]

This paper promotes reinforcement machine learning for route-finding tasks in quantum communication networks, where, due to the non-additivity of quantum errors, classical graph path or tree-finding algorithms cannot be used. We propose using a proximal policy optimization algorithm capable of finding routes in teleportation-based quantum networks. This algorithm is benchmarked against the Monte Carlo search. The topology of our network resembles the proposed 6 G topology and analyzed that quantum errors correspond to typical errors in realistic quantum channels. [ABSTRACT FROM AUTHOR]

The quantum permutation pad (QPP) is a cryptographic primitive, functionally similar to the one-time pad (OTP). Unlike OTP, QPP promises to remain secure even when the encryption key is used multiple times (Kuang and Barbeau in Quantum Inf Process 21(6):211, 2022. https://doi.org/10.1007/s11128-022-03557-y). QPP has emerged as a relatively recent proposal, with many aspects of its functionality yet to be explored. One such aspect is ensuring the security of this primitive against chosen-plaintext attacks. This study reveals that an eavesdropper can gain access to the encryption key under such an attack paradigm. Additionally, the security of a proposed practical encryption device built around PRNG and QPP primitives is examined (Kuang and Perepechaenko in EPJ Quantum Technol 9(1):26, 2022. https://doi.org/10.1140/epjqt/s40507-022-00145-y). We have found that simplified versions, in which the attacker has access to the input data of the QPP block, are vulnerable. It is crucial to note, however, that the described attack does not undermine the security of a complete implementation, as it requires a combined attack on both the PRNG and QPP. [ABSTRACT FROM AUTHOR]

Genuine multipartite entanglement is crucial for quantum information and related technologies, but quantifying it has been a long-standing challenge. Most proposed measures do not meet the "genuine" requirement, making them unsuitable for many applications. In this work, we propose a journey toward addressing this issue by introducing an unexpected relation between multipartite entanglement and hypervolume of geometric simplices, leading to a tetrahedron measure of quadripartite entanglement. By comparing the entanglement ranking of two highly entangled four-qubit states, we show that the tetrahedron measure relies on the degree of permutation invariance among parties within the quantum system. We demonstrate potential future applications of our measure in the context of quantum information scrambling within many-body systems. [ABSTRACT FROM AUTHOR]

Defining nonlocality in a no‐input closed quantum network scenario is a new area of interest nowadays. Gisin, in [Entropy 21, 325 (2019)], proposed a possible condition for non‐tri‐locality of the trivial no‐input closed network scenario, triangle network, by introducing a new kind of joint measurement bases and a probability bound. In [npj Quantum Information (2020) 6:70] they found a shred of numerical evidence in support of Gisin's probability bound. Now based on that probability bound, it finds the nature of the correlation in a triangle network scenario. This study observes how far the probability lies from that Gisin's bound with every possible combination of entangled and local pure states distributed from three independent quantum sources. Here, it uses the generalized Elegant Joint Measurements bases for each party and find that there is a dependency of non‐locality on the entanglement of these joint measurement bases. It also checks the probability bound for the polygon structure. [ABSTRACT FROM AUTHOR]

Quantum medical image encryption is one of the new methods to send medical images in an insecure communication channel. The proposed method is based on the flexible representation of quantum images which consists of two phases. In the first phase, the medical image is first interlaced using C-NOT gates and then the output of this phase is given to the second phase. In the second phase, one key is defined based on the logical mapping chaos function and the medical image encryption operation is performed based on this key. The output of the second phase is an encrypted image that can only be decrypted by the receiver which has the key. The results of the study of criteria such as histogram, entropy, correlation coefficient of adjacent pixels and correlation diagram show good performance. The entropy value of the proposed method is 99.67 which shows the proposed algorithm has much better performance than previous work. The temporal complexity of the designed quantum circuits is O(n), while the temporal complexity of the previous work is equal to O 2 2 n , which indicates the fast implementation of the proposed algorithm. [ABSTRACT FROM AUTHOR]

In the contemporary landscape, where a huge amount of data plays a vital role, the importance of strong and robust cybersecurity measures has become increasingly paramount. This research proposes a review and extensively explores cybersecurity techniques within the domain of machine/deep learning and quantum techniques, with a particular focus on cryptographic methods and methodologies applied to image encryption. The proposed survey covers a range of cybersecurity techniques, including quantum random number generation, secure transmission of quantum images, watermarking through quantum methods, and quantum steganography. Moreover, it explores the domain of image encryption, which integrates adversarial neural networks, deep learning and machine learning, transformation techniques, and chaotic neural networks that can be used to secure digital data from cyber attacks. Our focus extends beyond highlighting advances in investigating vulnerabilities in existing cryptographic techniques. By identifying the challenges and weaknesses, the potential solutions are also presented, establishing a foundation for future recommendations. These future suggestions address and overcome the vulnerabilities observed in existing cybersecurity techniques. The aim of the extensive survey and analysis of existing cryptographic techniques is to provide a deep understanding of innovative and diverse approaches within the cybersecurity domain. Simultaneously, it aims to create a roadmap for the future to counter potential cyber threats and challenges.

Abstract 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.

Abstract Quantum‐based technologies will provide system engineers with new capabilities for securing data communications. The UK AirQKD project has implemented a Free‐Space Optical Quantum Key Distribution (QKD) system to enable the continuous generation of symmetric encryption keys. One of the use cases for the generated keys is to secure Vehicle‐to‐Everything (V2X) communications. V2X applications would benefit from the certificate‐free security provided by QKD for a post‐quantum society. How FSO‐QKD could integrate into a V2X architecture is examined. An overview of V2X is provided with the role that FSO‐QKD could secure V2X data though some obstacles exist. One of the issues with 6G communications is the potential line‐of‐sight (LOS) considerations between the V2X devices. The modelling required for LOS is examined to analyse the outage performance of the building to infrastructure links in the 6G architecture. The results from the model show that further work is required if 6G LOS communications are going to be relied upon for future safety‐critical V2X applications.

Abstract The authors devised a protocol that allows two parties, who may malfunction or intentionally convey incorrect information in communication through a quantum channel, to verify each other's measurements and agree on each other's results. This has particular relevance in a modified version of the quantum coin flipping game. The key innovation of the authors’ work includes the new design of a quantum coin that excludes any advantage of cheating, by which the long‐standing problem of the fair design of the game is, affirmatively, solved. Furthermore, the analysis is extended to N‐parties communicating with each other, where multiple solutions for the verification of each player's measurement is proposed. The results in the N‐party scenario could have particular relevance for the implementation of future quantum networks, where verification of quantum information is a necessity.

Nowadays, pairing-based cryptography researchers are looking for new parameters for standard security levels against the new number field sieve tower number field sieve algorithm. Recently, they have suggested new parameters for well-studied pairing-friendly curves with odd embedding degrees five and seven resistant to this attack. In this paper, we define optimal ate pairing on curves using sparse families with embedding degrees five and seven. We also provide details to perform the miller loop and the final exponentiation using addition chain process. Our theoretical results costs indicate that these families of curves offer the best performance in the computation of the optimal ate pairing at the 128-bit security level compared to Cocks–Pinch curves of embedding degrees five and seven. The improvement is about 8 , 8 % and 1 9 % faster than the optimal ate pairing previously computed on Cocks–Pinch curves of embedding degrees five and seven, respectively. [ABSTRACT FROM AUTHOR]

The socialist millionaires' problem, emanating from the millionaires’ problem, allows two millionaires to determine whether they happen to be equally rich while remaining their riches undisclosed to each other. Most of the current quantum solutions to the socialist millionaires’ problem have lower efficiency and are theoretically feasible. In this paper, we introduce a practical quantum secure protocol for the socialist millionaires’ problem based on single photons, which can be easily implemented and manipulated with current technology. Our protocol necessitates the involvement of a semi-honest third party (TP) responsible for preparing the single-photon sequences and transmitting them to Alice who performs Identity or Hadamard operations on the received quantum sequences via her private inputs and the secret keys, producing new quantum sequences that are subsequently sent to Bob. Similarly, Bob encodes his private inputs into the received quantum sequences to produce new quantum sequences, which are then sent to TP. By conducting single-particle measurements on the quantum sequences received from Bob, TP can ascertain the equality of private inputs between Alice and Bob, and subsequently communicate the comparison result to them. To assess the feasibility, the proposed protocol is simulated on IBM Quantum Cloud Platform. Furthermore, security analysis demonstrates that our protocol can withstand attacks from outsiders, such as eavesdroppers, and from insider participants attempting to grab the private input of another participant.

We analyze the structure of Feigin-Stoyanovsky's principal subspaces of affine Lie algebra from the jet algebra viewpoint. For type A level one principal subspaces, we show that their shifted multi-graded Hilbert series can be expressed either using the quantum dilogarithm or as certain generating functions "counting" finite-dimensional representations of A -type quivers. This notably results in novel fermionic character formulas for these principal subspaces. Moreover, our result implies that all level one principal subspaces of type A are "classically free" as vertex algebras. We also analyze infinite jet algebras associated to principal subspaces of affine vertex algebras L 1 (so 5) , L 1 (so 8) and L 1 (g 2). We derive a new character formula for the principal subspace of L 1 (so 5) , proving that it is classically free, and present evidence that the principal subspaces of L 1 (so 8) and of L 1 (g 2) are also classically free. [ABSTRACT FROM AUTHOR]

During the COVID pandemic caused by the SARS-CoV-2 virus, studies have shown the efficiency of deactivating this virus via ultraviolet light. The damage mechanism is well understood: UV light disturbs the integrity of the RNA chain at those locations where specific nucleotide neighbors occur. In this contribution, we present a model to address certain gaps in the description of the interaction between UV photons and the RNA sequence for virus inactivation. We begin by exploiting the available information on the pathogen's morphology, physical, and genomic characteristics, enabling us to estimate the average number of UV photons required to photochemically damage the virus's RNA. To generalize our results, we have numerically generated random RNA sequences and checked that the distribution of pairs of nucleotides susceptible of damage for the SARS-CoV-2 is within the expected values for a random-generated RNA chain. After determining the average number of photons reaching the RNA for a preset level of fluence (or photon density), we applied the binomial probability distribution to evaluate the damage of nucleotide pairs in the RNA chain due to UV radiation. Our results describe this interaction in terms of the probability of damaging a single pair of nucleotides, and the number of available photons. The cumulative probability exhibits a steep sigmoidal shape, implying that a relatively small change in the number of affected pairs may trigger the inactivation of the virus. Our light-RNA interaction model quantitatively describes how the fraction of affected pairs of nucleotides in the RNA sequence depends on the probability of damaging a single pair and the number of photons impinging on it. A better understanding of the underlying inactivation mechanism would help in the design of optimum experiments and UV sanitization methods. Although this paper focuses on SARS-CoV-2, these results can be adapted for any other type of pathogen susceptible of UV damage. [ABSTRACT FROM AUTHOR]

The technological advancements made in recent times, particularly in artificial intelligence (AI) and quantum computing, have brought about significant changes in technology. These advancements have profoundly impacted quantum cryptography, a field where AI methodologies hold tremendous potential to enhance the efficiency and robustness of cryptographic systems. However, the emergence of quantum computers has created a new challenge for existing security algorithms, commonly called the 'quantum threat'. Despite these challenges, there are promising avenues for integrating neural network-based AI in cryptography, which has significant implications for future digital security paradigms. This summary highlights the key themes in the intersection of AI and quantum cryptography, including the potential benefits of AI-driven cryptography, the challenges that need to be addressed, and the prospects of this interdisciplinary research area. [ABSTRACT FROM AUTHOR]

Quantum secret sharing plays a crucial role in quantum cryptography. In this paper, we present a rational hierarchical (t,n)-threshold quantum secret sharing scheme based on Lagrange interpolation. In our scheme, participants possess rational and hierarchical properties, and the secret can be reconstructed when the number of rational participants satisfies the hierarchical (t,n)-threshold structure proposed in this paper. The reconstructed secret can encompass both classical information and quantum state information, enhancing the practicality and flexibility of our scheme compared to existing ones. Additionally, we redefine the utility of participants based on their roles in the secret recovery process. This newly defined utility allows for a more precise analysis of the correctness, fairness, and equilibrium of our scheme. Finally, our scheme not only resists a typical set of external attacks but also incorporates mechanisms to detect forgery and collusion among participants. [ABSTRACT FROM AUTHOR]

Proposed by Hillery et al., Quantum Secret Sharing (QSS) is a technique used to break a quantum secret into multiple pieces (called Shares), such that any proper subset of the pieces does not reveal any information about the original secret. The secret can be reconstructed only when all of the pieces are combined together. However, most of the QSS protocols assume that the shares are untampered, hence fail to regenerate the original secret if some of the shares are damaged due to several reasons like cheating participants, eavesdropping, etc. In order to tackle this practical challenge, Resilient Quantum Secret Sharing (RQSS) protocols are required. In this paper, we propose an RQSS protocol that uses Quantum Error Correcting Codes (QECC) for share generation and secret reconstruction. Our protocol generates n shares of a m-qubit quantum secret, owned by the dealer, and distributes it among nparticipants; moreover, it can regenerate the original secret even if k < n shares are damaged. To the best of our knowledge, no such generalized protocol exists in the available literature. [ABSTRACT FROM AUTHOR]

Quantum secret sharing is widely applied in the fields, such as communications and data transmission. In this paper, we propose an authenticable dynamic quantum multi-secret sharing scheme based on the Chinese remainder theorem. In our scheme, the dynamic update of the participants set is permissible without changing the shared secret. To share multi-secret, the distributor generates corresponding shares based on the Chinese remainder theorem and monotone span program, and the GHZ state acts as the information carrier traveling among the participants in the authorization set; the participants utilize the Hadamard operator and Pauli operators to embed their shares in the traveling particles. In this way, the participants will reconstruct multiple secrets. Furthermore, the proposed quantum digital signature algorithm based on entanglement swapping is utilized to realize the identity authentication between participants. The security analysis shows that the proposed scheme can resist intercept-resend attack, entanglement-measurement attack, internal dishonest participant attack, add or withdraw participant attack, and denial attack. [ABSTRACT FROM AUTHOR]

In a secure communication network, multiparty quantum key agreement (MQKA) is crucial for providing multiple participants with secret keys in a fair manner. To address the needs of both multiparty secure communication and point-to-point secure communication simultaneously, this paper introduces a novel two-layer multiparty quantum key agreement (TMQKA) protocol with collective detection, based on non-maximum entangled states. The first-layer agreement key is established among multiple participants to enable secure multiparty communication. The second-layer agreement key is established between any two participants to enable point-to-point secure communication. The generation of two-layer keys improves the efficiency of the protocol. In addition, we demonstrate that the proposed TMQKA protocol satisfies the requirements of correctness, security, and fairness. This paper presents a theoretical exploration of TMQKA, contributing to the expanding body of research on multiparty quantum cryptography. Our work represents an attempt to develop secure communication protocols for practical applications. [ABSTRACT FROM AUTHOR]

The emergence of new complex technologies, such as cloud and quantum computing, has a complicated computational structure, which can compromise the security of traditional cryptographic protocols. It has been noted that traditional security systems utilize non-quantum resistance factorization and Diffie–Hellman (DH) hard problems for their protection. Lattice-based cryptography appears to be a potential post-quantum substitute for the presently employed public-key cryptography. As a result, we have been motivated to focus on increasingly sophisticated and challenging lattice hard assumptions capable of withstanding new modern technologies with quantum resistance properties. In this paper, we devise a new lattice-based public-key encryption and signature schemes with smaller key sizes. The proposed scheme also resists the quantum attack because of the lattice small integer solution problem and its variant. The security claim has also been proved in a well-suited model for quantum attacks. The performance analysis shows that the presented schemes outperform the DH-type schemes and compete with similar lattice-based schemes in terms of storage, communication, key sizes, and computational overheads. [ABSTRACT FROM AUTHOR]

Quantum-key-distribution (QKD) networks are gaining importance and it has become necessary to analyze the most appropriate methods for their long-distance interconnection. In this paper, four different methods of interconnecting remote QKD networks are proposed. The methods are used to link three different QKD testbeds in Europe, located in Berlin, Madrid, and Poznan. Although long-distance QKD links are only emulated, the methods used can serve as a blueprint for the secure interconnection of distant QKD networks in the future. Specifically, the presented approaches combine, in a transparent way, different fiber and satellite physical media, as well as common standards of key delivery interfaces. The testbed interconnections are designed to increase the security by utilizing multipath techniques and multiple hybridizations of QKD and post-quantum cryptography (PQC) algorithms. [ABSTRACT FROM AUTHOR]

Elliptic curve cryptography is a widely deployed technology for securing digital communication. It is the basis of many cryptographic primitives such as key agreement protocols, digital signatures, and zero-knowledge proofs. Fast elliptic curve cryptography relies on heavily optimised modular arithmetic operations, which are often tailored to specific micro-architectures. In this article, we study and evaluate optimisations of the popular elliptic curve Curve25519 for ARM processors. We specifically target the ARM NEON single instruction, multiple data (SIMD) architecture, which is a popular architecture for modern smartphones. We introduce a novel representation for 128-bit NEON SIMD vectors, optimised for SIMD parallelisation, to accelerate elliptic curve operations significantly. Leveraging this representation, we implement an extended twisted Edwards curve Curve25519 back-end within the popular Rust library "curve25519-dalek". We extensively evaluate our implementation across multiple ARM devices using both cryptographic benchmarks and the benchmark suite available for the Signal protocol. Our findings demonstrate a substantial back-end speed-up of at least 20% for ARM NEON, along with a noteworthy speed improvement of at least 15% for benchmarked Signal functions. [ABSTRACT FROM AUTHOR]

Quantum sciences and technologies introduce a new arena whose applications are widely used in the microscopic world. Quantum communication is also an important branch of quantum science by which we intend to transmit quantum information. Quantum teleportation is important because it uses the entanglement principle which is unique in quantum space to transmit quantum information. In fact, in this type of protocol, no information is sent and everything is transmitted using the miracle of entanglement. In this paper, an attempt is made to present a quantum teleportation scheme that, unlike the other designs, can change the destination of qubits. This means that at the beginning of the protocol, the receivers have no idea who has sent the qubits, and the controller decides how these communications will work. At last, noise analysis is presented. [ABSTRACT FROM AUTHOR]

This document is an editorial summarizing the Applied Geometric Algebras in Computer Science and Engineering (AGACSE) conference held in Brno, Czech Republic in September 2021. The conference aimed to promote the use of geometric algebra in fields such as image processing, robotics, and quantum computing. The conference proceedings were published in the journal Mathematical Methods in the Applied Sciences. The editorial provides a list of accepted papers, covering topics such as applied geometry, technological applications, algebra, and quantum phenomena. One specific paper explores the use of geometric algebra in teaching rotations through neural networks. The document is a compilation of research papers showcasing the applications of geometric algebra in various fields, including robotics, control systems, image processing, cryptography, and physics. Each paper presents a specific problem or application and proposes a unique approach or solution using geometric algebra. The authors compare their methods with existing techniques and provide mathematical analysis to support their claims. Overall, the papers demonstrate the versatility and effectiveness of geometric algebra in different domains. [Extracted from the article]