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Local hidden-variable model of singlet-state correlations discussed in Czachor (Acta Phys Polon A 139:70, 2021a) is shown to be a particular case of an infinite hierarchy of local hidden-variable models based on an infinite hierarchy of calculi. Violation of Bell-type inequalities can be interpreted as a 'confusion of languages' problem, a result of mixing different but neighboring levels of the hierarchy. Mixing of non-neighboring levels results in violations beyond the Tsirelson bounds. [ABSTRACT FROM AUTHOR]

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]

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 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]

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]

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]

In the field of post-quantum security, isogeny-based cryptography stands out for its ability to fight quantum attacks. One of the key operations in isogeny-based schemes is finite field multiplication, which plays a crucial role in cryptographic protocols such as key exchange and digital signatures. To ensure practical implementations of these schemes, efficient finite field multiplication is essential. In this research, a novel optimization approach, the Crossover-Boosted Water Cycle Algorithm (CB-WCA), to enhance the efficiency of finite field multiplication in isogeny-based cryptography is proposed. By using both the WCA and a crossover method inspired by genetic algorithms, the CB-WCA effectively explores solution areas, aiming for the best solutions. The formulation of the finite field multiplication optimization problem and an objective function that quantifies the efficiency of the multiplication process based on computational cost is presented and defined. The CB-WCA is then applied to find the optimal set of parameters for finite field multiplication algorithms. Extensive experimental evaluations are conducted, comparing the performance of the CB-WCA-optimized algorithms with traditional optimization methods and other metaheuristic algorithms. Through the findings, it is evident that the CB-WCA stands out for its ability to achieve faster execution times and decrease computational costs. Furthermore, the optimized finite field multiplication algorithms are integrated into isogeny-based cryptographic schemes and evaluate their impact on cryptographic protocol efficiency and security. Real-world implementations showcase the practical applicability of the optimized algorithms in hardware and software environments. To ensure the security of the optimized algorithms, rigorous cryptanalysis is performed to verify their resilience against potential attacks, ensuring they meet the highest standards of security. [ABSTRACT FROM AUTHOR]

Semi-quantum signature is an important research topic in quantum cryptography. Based on the Bell states, a semi-quantum signature scheme with arbitrator is proposed. In our scheme, the quantum signer signs the message by encoding the ciphtext with the Bell states and performing the controlled NOT gate on the particles, while the signature receiver and arbitrator corporately verify the signature by measuring the received qubits with Z-basis. Compared with the similar schemes, ours has the better performances as follows. (1) It can be proved to be information-theoretically secure. It has the strong undeniability property. (2) The signer is a quantum partner, while both the signature receiver and the arbitrator are classical partners. (3) The signer needn't share any private key with the receiver. (4) The scheme is based on Bell state, which is relatively easier to be prepared than the other entanglement resources used in the similar schemes. (5) It has better qubit efficiency. Therefore, our scheme has better performances in security, practicability and efficiency than the similar schemes. [ABSTRACT FROM AUTHOR]

Time synchronization is one of the most crucial issues that must be addressed in developing quantum key distribution (QKD) systems. It not only lets the transmitter and the receiver to assign a sequence number to each event and then do correct basis reconciliation, but also allows to increase signal-to-noise ratio. Time synchronization in satellite communications is especially complicated due to such factors as high loss, signal fading, and Doppler effect. In this work, a simple, efficient, and robust algorithm for time synchronization is proposed. It was tested during experiments on QKD between Micius, the world's first quantum communications satellite, and an optical ground station located in Russia. The obtained synchronization precision lies in the range from 467 to 497 ps. The authors compare their algorithm for time synchronization with the previously used methods. The proposed approach can also be applied to terrestrial QKD systems. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel scheme with a semi-honest third party (TP) to compute the intersection of two parties' sets privately. In our scheme, two groups of particles are firstly prepared by TP and then transmitted circularly among TP and two participants who need the intersection of their private sets. The two participants then perform the unitary operations on their received particles according to an initial encoding rule for their private sets, respectively, to help TP to obtain the result. We analyse the security of our scheme and show that it can resist both outside and inside attacks over ideal and noisy quantum channels. In addition, our scheme is feasible with current quantum technologies as it only requires simple quantum resources and operations. [ABSTRACT FROM AUTHOR]

In many communication scenarios, it is necessary to involve a third party for control and supervision. In the context of controlled bidirectional quantum secure direct communication (CBQSDC) protocols, the transmission of secret messages between two legitimate users is only permitted with the explicit permission of a controller. To address the issue of controlled communication, a CBQSDC protocol (CLYH2015) utilizing Bell states was proposed in the paper (Quant Inf Process 14, 3515–3522, 2015). Bell states have been widely recognized for their significance in the field of quantum secure direct communication. In a subsequent study published in (Quant Inf Process 16, 147, 2017), the research examined whether CLYH2015 protocol strictly requires the initial states to be Bell states. The conclusion drawn from this investigation is that CLYH2015 protocol working properly necessitates the use of Bell states as initial states. To explore alternative possibilities for the initial states in CLYH2015 protocol, a class of CBQSDC protocols employing the generalized Bell states (GBell states), a | 00 ⟩ + b | 11 ⟩ , b ¯ | 00 ⟩ - a ¯ | 11 ⟩ , a | 01 ⟩ + b | 10 ⟩ , and b ¯ | 01 ⟩ - a ¯ | 10 ⟩ , are designed where a and b are complex numbers with | a | = | b | = 1 2 , a ¯ and b ¯ the conjugate complex numbers of a and b, respectively. The class of designed CBQSDC protocols demonstrates several favorable properties, including resistance against information leakage, intercept-and-resend attacks, measure-resend attacks, as well as robustness against collective attacks. In addition, the unconditional security of the class of designed protocols is proved. Finally, to show the advantages of the class of designed protocols, they are compared with some with some previous closely associated protocols. Interestingly, it is worth noting that the Bell states can be considered a special case of the GBell states when both a and b are real numbers. Consequently, CLYH2015 protocol can be regarded as a particular instance of the designed CBQSDC protocols. This insight implies that the initial states in CLYH2015 protocol can be extended to include the GBell states, rather than being limited solely to the Bell states. [ABSTRACT FROM AUTHOR]

MQTT, a popular IoT messaging protocol, is frequently associated with numerous vulnerabilities, the majority of which are critical. Many IoT devices that utilize MQTT are susceptible to cyberattacks such as denial-of-service and buffer overflow. In this paper, we unveil a novel Denial of Service (DoS) attack in the MQTT protocol, referred to as Slow Subscribers, which has the potential to cause MQTT brokers to become single points of failure. Unlike existing MQTT DoS attacks, Slow Subscribers can occur on a single compromised node and could potentially disrupt a MQTT broker with minimal subscription permissions. We evaluated the reliability of Mosquitto and NanoMQ, two popular MQTT messaging brokers, to determine the effect of Slow Subscribers. According to the findings of our investigation, NanoMQ outperforms Mosquitto in response to the Slow Subscribers attack at QoS level 0. We also determine that the response to Slow Subscribers at QoS 2 is the worst for both broker implementations. In addition, the results of our experiments indicate that Eclipse Mosquitto achieves a higher rate of reliability than NanoMQ on cloud deployments whereas NanoMQ has proven to be well-suited for edge environments, especially edge IoT devices that require the use of QoS levels 0 and 1. Finally, we propose a Resilient Middleware for Message Queue Telemetry Transport (Remistry) framework that is capable of detecting misconfigurations while providing granular support of resource commitment errors, in particular the out-of-memory (OOM) problems for effectively mitigating the impact of Slow Subscribers attacks on MQTT brokers. [ABSTRACT FROM AUTHOR]

An original CSIKE post-quantum cryptography algorithm is proposed as a modification of the CSIDH algorithm but with one public key instead of two. The conditions for its implementation on two classes of non-cyclic Edwards curves are substantiated. The properties of quadratic and twisted supersingular Edwards curves that form pairs of quadratic twist of order p + 1 ≡ 0 mod 8 over a prime field Fp are considered. A modification of the CSIDH algorithm and the CSIKE algorithm are presented, which are generated on the isogenies of these curves instead of the traditional arithmetic of curves in the Montgomery form. For isogenies of degrees 3, 5, and 7, the parameters of isogenic chains of non-cyclic supersingular Edwards curves are calculated and tabulated for p = 839. The implementation of the key encapsulation scheme with its encryption by Alice with Bob's public key is considered. A new randomized CSIKE algorithm with random equiprobable selection of the curve from two classes at each step of the isogeny chain is proposed. The probability of a successful side-channel attack in a randomized algorithm is estimated. It is proposed to abandon the calculation of the isogenic function ϕ(R) of a random point R, which significantly speeds up the algorithm. [ABSTRACT FROM AUTHOR]

Most of current public key cryptosystems would be vulnerable to the attacks of the future quantum computers. Post-quantum cryptography offers mathematical methods to secure information and communications against such attacks, and therefore has been receiving a significant amount of attention in recent years. Lattice-based cryptography, built on the mathematical hard problems in (high-dimensional) lattice theory, is a promising post-quantum cryptography family due to its excellent efficiency, moderate size and strong security. This survey aims to give a general overview on lattice-based cryptography. To this end, the authors begin with the introduction of the underlying mathematical lattice problems. Then they introduce the fundamental cryptanalytic algorithms and the design theory of lattice-based cryptography. [ABSTRACT FROM AUTHOR]

In the current scenario of information explosion, one of the growing concerns of scientists worldwide is to manage the information storage and transmission by realizing the novel and reliable means of secure communication of data and information. This is essential to avoid any threat of the breaching of secret information on the part of hackers during the communication. In this regard, in contrast to routine classical methods, state-of-the-art robust quantum methods of secure communication such as quantum cryptography and Internet of Things (IoTs) information via quantum coherence medium and quantum networking of IoTs are gaining immense interest. In this context, chiral atomic medium and 2D materials such as graphene have attracted tremendous research interest. This owes to their remarkable linear and nonlinear ultrafast response and tunable structural and optoelectronic properties, which have potential applications in quantum computing, quantum information processing, information storage, and secure communication of IoTs information. In this paper, we explore the potential of Landau-quantized graphene (LQG) for secure communication of IoTs information by investigating quantum coherence-based propagation of light and optical properties of LQG. We report on the tunable optical response of a newly-proposed four-level ladder-type LQG subject to a weak probe field in conjunction with two strong control fields. In particular, employing the density-matrix approach, we report on theoretical analysis of superluminal/subluminal and absorption-free light propagation via quantum coherence in view of tunable electromagnetically induced transparency. Based on the tunable optical response of LQG, we propose a quantum networking model for the secure communication of quantum information via IoTs quantum networking. [ABSTRACT FROM AUTHOR]

Quantum secure direct communication is an important branch of quantum cryptography. One of the main requirements of quantum secure direct communication is to ensure that no secret information can be stolen. Recently, a bidirectional quantum secure direct communication protocol [Quantum Information Processing 16, 147 (2017)] was proposed. It was believed that the intercept-and-resend attack and information leakage problem can be avoided via this protocol. However, in this paper, we point out that attackers can obtain useful information about the secret messages by constructing two intercept-and-resend attacks on the above protocol. Attackers can obtain Alice's secret message exclusive OR Bob's secret message by the first attack and both secret messages by the second attack. To resist the two constructed attacks, we design an improved bidirectional quantum secure direct communication protocol. Furthermore, we show that the designed protocol can resist the two constructed attacks and its efficiency has increased. It is interesting that the designed protocol can publish Alice's result states, i.e., Bob's initial states, without affecting its security. The designed protocol can prevent Alice (Bob) from obtaining Bob's (Alice's) secret message before Alice (Bob) sends her (his) secret message. This work can notice researchers to avoid similar security problems in constructing quantum cryptography protocols. [ABSTRACT FROM AUTHOR]

This work researches the implementation of the AES family with Pauli-X gates, CNOT gates and Toffoli gates as the underlying quantum logic gate set. First, the properties of quantum circuits are investigated, as well as the influence of Pauli-X gates, CNOT gates and Toffoli gates on the performance of the circuits constructed with those gates. Based on these properties and the observations on the hardware circuits built by Boyar et al. and Zou et al., it is possible to construct quantum circuits for AES's Substitution-box (S-box) and its inverse (S-box - 1 ) by rearranging the classical implementation to three parts. Since the second part is treated as a 4-bit S-box in this paper and can be dealt with by existing tools, a heuristic is proposed to search optimized quantum circuits for the first and the third parts. In addition, considering the number of parallelly executed S-boxes, the trade-offs between the qubit consumption and T · M values for the round function and key schedule of AES are studied. As a result, quantum circuits of AES-128, AES-192 and AES-256 can be constructed with 269, 333 and 397 qubits, respectively. If more qubits are allowed, quantum circuits that outperform state-of-the-art schemes in the metric of T · M value for the AES family can be reported, and it needs only 474, 538 and 602 qubits for AES-128, AES-192 and AES-256, respectively. [ABSTRACT FROM AUTHOR]

Comprehensive inquisition of wireless communication with flexible quantum electronics and physics can be considered as one of the blooming technology. Quantum Cryptography which extends from combination of quantum electronics and physics is one of the best technology that helps to transfer data securely between various user's, due to its rudimentary concept of Quantum Key Distribution (QKD). There are two major concerns in the communication. The first concern is for the data transmission which is frequently carried out through some entity of the cellular network such as Home subscriber Server (HSS) or Gateway (GW), and Evolved Node B(eNB), which is inadvisable to preserve confidentiality of the message. The second concern is, device-to-device (D2D) communication via prose function which is relatively a threat affected path that can be easily affected by the man in the middle (MitM) attack, message drop attack, replay attack, denial of service (DoS) attack, impersonation attack.. To mitigate these threats, this research work is proposing a Secure Authentication Protocol (SAP). The proposed SAP is categorized into 5 phases namely framework of network, enrolment phase, D2D discovery phase, key production—authentication phase and content conveyance phase. Framework of network phase generates function parameters. Enrolment phase registers all user equipment (UE) for verification and also generate an appropriate user application code for respective UE. In this phase, HSS also manages a database that contains detail about all the enrolled. D2D discovery phase allows the UE to discover the neighbors under that proximity area. During the authentication phase, public as well as private secret keys are generated using Elliptic Curve Cryptography (ECC) and Elliptic Curve Diffie-Hellman (ECDH) algorithm. In addition to that, this phase implements hash based message authentication code (HMAC) to create application associated keys. In the last phase of content conveyance, most important step is to share Shared Secret Key (SSK) as it mainly responsible while decrypting original message. To make this transmission very secure, quantum channel is used. Quantum Cryptography plays a vital role in this phase for providing security to whole transmission process at high level. Now a days, advanced optical technologies are also using quantum cryptography to establish secured communication. The performance of the proposed SAP is evaluated and compared with the existing protocols by using multiple evaluation criteria such as cost of operation, computational overhead, storage overhead and energy consumption. This article also provides insights into various security threats such as MitM, replay attack, DoS attack, impersonation attack, known key attack due to use of ECC and ECDH. Also, SAP provides a strong pillar against eavesdropping attack due to quantum cryptography. Also, Bennett and Gilles Brassard (BB84) protocol linked with quantum electronics and physics, place a significant role for creation of quantum channel over classical channel, which took security of SAP at next level. [ABSTRACT FROM AUTHOR]

Based on three-particle pure states, a new anonymous semi-quantum privacy comparison is proposed to deal with the threat of quantum computing power faced by users without complete quantum capabilities in the post-quantum era. In this scheme, quantum entanglement and quantum uncertainty principles are used to ensure third party security, measurement attack security and entanglement attack security. Compared with most semi-quantum privacy comparison schemes, it reduces the risk of TP evil and improves communication efficiency. Therefore, the scheme has stronger safety and higher efficiency. [ABSTRACT FROM AUTHOR]

Quantum secret sharing is one of the important techniques in quantum cryptography. In this paper, we propose a novel dynamic hierarchical quantum secret sharing scheme with general access structure. Participants from different levels share the same secret. Firstly, a special hierarchical structure based on the generalized GHZ state is constructed, which expands the application value of the existing hierarchical quantum secret sharing. Secondly, this paper uses the monotone span program (MSP) and the generalized Pauli operator to realize the dynamic property of the scheme, which includes three aspects: The hierarchical access structure is variable; participants can join or leave, and the shared secret can be updated. Moreover, the shares of the participants can be protected so as to reduce communication consumption due to reuse of the shares. Finally, compared with other hierarchical quantum secret sharing schemes, the proposed scheme is not only more flexible but also more secure. [ABSTRACT FROM AUTHOR]

Quantum one-way function provides security for cryptographic protocols in quantum cryptography. Full quantum one-way function is a type of quantum one-way function that maps between quantum states and deals with pure quantum information. It was initially proposed by means of concatenating 'quantum–classical' and 'classical–quantum' quantum one-way functions. The first full quantum one-way function can be applied to quantum authentication, which uses quantum states to authenticate quantum states directly. However, the concatenation format restricts the implementation and cryptographic applications of this function. Considering the advantage of quantum circuit optimization in implementing quantum circuits to physical quantum devices, we propose a dynamic full quantum one-way function based on quantum circuit mapping. Quantum circuit optimization intrinsically generates the remapped quantum circuit which maps between quantum states but does not destroy them. The dynamic process of quantum circuit mapping contributes to the one-wayness of the dynamic full quantum one-way function. The experimental results show that this function is more realizable than the concatenated full quantum one-way function. The dynamic full quantum one-way function can be employed to construct a full quantum trapdoor one-way function which is 'easy to compute and invert' based on a trapdoor. Meanwhile, this new full quantum one-way function is proved to be very useful in quantum cryptography, especially in quantum currency notes. Our work promotes the development from full quantum one-way functions to future quantum cryptographic applications. [ABSTRACT FROM AUTHOR]

Handover authentication and key agreement protocol is extremely essential to ensure the security of the Internet of Things (IoT), and it enables mobile devices to access roaming services in the trust domain of the foreign agent. The energy and computing capabilities of mobile devices are extremely limited, and the requirements for storage and computing efficiency are higher in IoT. The problem of large integer decomposition and discrete logarithm can be solved in polynomial time on a quantum computer, which makes the massive traditional handover authentication and key agreement protocols based on bilinear pairing and elliptic curve cryptography no longer safe. Due to the participation of the home agent, the traditional handover authentication protocol has a long communication delay and is vulnerable to the session key compromise attacks. Moreover, the session key between the foreign agent and the home agent is randomly specified in advance, and its generation process is not given, which has poor security and is easy to cause the leakage of the session key. Lattice cipher based on NTRU is the lightweight public key primitive that can resist quantum attacks and has a faster calculation speed and smaller key length, which is more suitable for IoT. Therefore, we proposed a secure and lightweight two-party handover authentication protocol based on NTRU for the mobile device without the home agent to prevent these deficiencies. We employ the BAN logic to validate the correctness of the proposed protocol and utilize the random oracle model to evaluate the security of the proposed protocol. In contrast with other current handover authentication protocols, the proposed protocol has greater security, higher efficiency, and lower communication overhead. [ABSTRACT FROM AUTHOR]

As an important practical cryptographic protocol, quantum key distribution (QKD)-based quantum private query (QPQ) has gained widespread attention in the past few decades. However, many of these protocols require classical post-processing, and the number of transmitted qubits is often much larger than the size of the database. Recently, Zhou et al. proposed a QPQ protocol that uses the W state and relies on a third party, which only requires qubits of the same size as the database [37]. Unfortunately, we have discovered a potential attack strategy against this protocol. By using fake entangled photons, a dishonest third party may be able to compromise the privacy of both the database owner and the user. To address this security vulnerability, we propose an improved QPQ protocol. [ABSTRACT FROM AUTHOR]

Multiparty quantum private comparison (MQPC) protocol enables the comparison of the private information of n parties through the combination of quantum mechanics with classical private comparison. In order to improve efficiency and practicality, this paper proposes an efficient MQPC protocol based on single photons and rotation encryption with the assistance of a semi-honest third party (TP). TP participates in preparing the initial single photon sequence, which is encrypted and sent to the participants one by one. The private inputs of participants are encoded into particular rotation angles that are used to convert the received single photon sequence to an unknown quantum state sequence, which is returned to TP in a closed-loop transfer mode. By implementing rotation encryption and multiplexing of single photons, the qubit efficiency and practicality of the protocol can be significantly improved, without the need for complex quantum technologies, such as entanglement swapping of high-dimensional quantum states, maximal entanglement states with n-particle and entanglement correlation between various particles in a quantum state. Moreover, the proposed protocol is simulated on IBM Quantum Experience to show its feasibility. Security analysis demonstrates that the proposed protocol is resistant to different types of attacks. [ABSTRACT FROM AUTHOR]

Quantum information stored in a qubit is rapidly lost to the environment. The realization of robust qubits is one of the most important challenges in quantum computing. Herein, we propose to embed a logical qubit within the manifold of a qudit as a scheme to preserve quantum information over extended periods of time. Under identical conditions (e.g., decoherence channels), the submanifold of the logical qubit exhibits extended lifetimes compared to a pure two-level system (qubit). The retention of quantum information further improves with separation between the sublevels of the logical qubit. Lifetime enhancement can be understood in terms of entropy production of the encoding and nonencoding subspaces during evolution under a quantum map for a d-level system. The additional pathways for coherent evolution through intermediate sublevels within a d-level manifold provide an information-preserving mechanism: reversible alternative channels to the irreversible loss of information to the environment characteristic of open quantum systems. [ABSTRACT FROM AUTHOR]

In this paper, we prove the unconditional security of a single-state circular mediated semi-quantum key distribution protocol. It starts with a third-party quantum server, TP, sending a string of qubits sequentially through two classical users Alice and Bob, and finally back to TP. We derive an expression for the key rate in the asymptotic scenario. When the communication parties Alice and Bob observe that the error rate is less than a determined threshold, the key rate is always greater than 0, so they can distill a string of secure secret keys. At the end of this paper, we extend this protocol to the multiple users case, where more than two classical users establish a string of security keys. [ABSTRACT FROM AUTHOR]

Traditional radio frequency identification (RFID) research mainly focused on enhancing the security of RFID protocol in different RFID applications like supply chains based on a centralized database. Secure and transparent transmission of goods is one of the prime issues in the supply chain management system. Bandwidth is the essential factor that affects the safe transition of goods in the supply chain. To fulfil bandwidth requirements, the 5G-enabled Internet of Things is a solution in the domain of Mobile edge computing. To successfully fill this gap, we present a secure, efficient ultra-lightweight blockchain-enabled RFID authentication protocol suitable for a supply chain in the field of 5G with mobile edge computing named ULBRAPS. Next, Blockchain is the core technology that provides data security, transparency, and scalability and prevents counterfeiting in supply chain management. Our proposed ULBRAPS comprises a one-way cryptographic secure hash function, bit-by-bit exclusive-or (XOR), and bit-by-bit rotation operation. Besides this, intensive security analysis of the presented protocol is performed on the extensively accepted AVISPA tool, confirming that ULBRAPS is secure. Eventually, ULBRAPS is proven outstanding efficient, safe, and has better computational and communication costs than other relevant protocols. [ABSTRACT FROM AUTHOR]

This paper proposes a new private comparison protocol based on four-dimensional three-particle GHZ-like states. The QPC protocol allows two participants with limited quantum abilities to compare their private information whether they are equal or not with the help of a semi-honest third party. The semi-honest third party means that it may be unfaithful on his own behavior, though it will execute the protocol loyally. The presented QPC protocol not only reduces the requirement on quantum operations without involving the unitary operation, but it also requires only the single-particle measurement. The quantum circuit of the six-qubit state and the measurement results are presented under the IBM Quantum Experimental platform. The correctness and the effectiveness of the suggested protocol are illustrated with some examples. In addition, detailed security analysis demonstrates that the proposed two-party QPC protocol is secure against the internal and external attacks. [ABSTRACT FROM AUTHOR]

In this work, the nonlocal quantum orthogonal product state (OPB) is first used to design a multi-party private comparison protocol, where multiple participants could securely compare the size of their private inputs. The ring topology is adopted for participants communicating with each other, which can significantly reduce the amount of information that the third party needs to process. But compared with the star topology, the ring topology is more vulnerable to the threat of participant attacks. Using the nonlocal OPB as the transmitted states can deal with this problem well, which prevents dishonest participants from obtaining valuable information related to the transmitted state. Vector coding, decoy particles, and random numbers are also used to promise the security of the protocol. In addition, this work requires less quantum capability. Compared with entangled states, nonlocal OPB is easier to prepare, and the operations that the participants need to perform are simple. The pre-shared key is not required, which consumes fewer quantum resources. [ABSTRACT FROM AUTHOR]

Every multipartite entangled quantum state becomes fully separable after an entanglement breaking quantum channel acted locally on each of its subsystems. Whether there are other quantum channels with this property has been an open problem with important implications for entanglement theory (e.g., for the distillation problem and the PPT squared conjecture). We cast this problem in the general setting of proper convex cones in finite-dimensional vector spaces. The max-entanglement annihilating maps transform the k-fold maximal tensor product of a cone C 1 into the k-fold minimal tensor product of a cone C 2 , and the pair (C 1 , C 2) is called resilient if all max-entanglement annihilating maps are entanglement breaking. Our main result is that (C 1 , C 2) is resilient if either C 1 or C 2 is a Lorentz cone. Our proof exploits the symmetries of the Lorentz cones and applies two constructions resembling protocols for entanglement distillation: As a warm-up, we use the multiplication tensors of real composition algebras to construct a finite family of generalized distillation protocols for Lorentz cones, containing the distillation protocol for entangled qubit states by Bennett et al. (Phys Rev Lett 76(5):722, 1996) as a special case. Then, we construct an infinite family of protocols using solutions to the Hurwitz matrix equations. After proving these results, we focus on maps between cones of positive semidefinite matrices, where we derive necessary conditions for max-entanglement annihilation similar to the reduction criterion in entanglement distillation. Finally, we apply results from the theory of Banach space tensor norms to show that the Lorentz cones are the only cones with a symmetric base for which a certain stronger version of the resilience property is satisfied. [ABSTRACT FROM AUTHOR]

Wireless body sensor network (WBSN) is an interdisciplinary field that could permit continuous health monitoring with constant clinical records updates through the Internet. WBAN is a special category of wireless networks. Coronavirus disease 2019 (COVID-19) pandemic creates the situation to monitor the patient remotely following the social distance. WBSN provides the way to effectively monitor the patient remotely with social distance. The data transmitted in WBSN are vulnerable to attacks and this is necessary to take security procedure like cryptographic protocol to protect the user data from attackers. Several physiological sensors are implanted in the human body that will collect various physiological updates to monitor the patient's healthcare data remotely. The sensed information will be transmitted wirelessly to doctors all over the world. But it has too many security threats like data loss, masquerade attacks, secret key distribution problems, unauthorized access, and data confidentiality loss. When any attackers are attacking the physiological sensor data, there is a possibility of losing the patient's information. The creation, cancellation, and clinical data adjustment will produce a mass effect on the healthcare monitoring system. Present-day cryptographic calculations are highly resistant to attacks, but the only weak point is the insecure movement of keys. In this paper, we look into critical security threats: secure key distribution. While sharing the secret key between communicating parties in the wireless body sensor networks in the conventional method like via phone or email, the attackers will catch the private key. They can decrypt and modify more sensitive medical data. It can cause a significant effect like death also. So need an effective, secure key distribution scheme for transmission of human body health related data to medical professional through wireless links. Moreover, a new enhanced BB84 Quantum cryptography protocol is proposed in this paper for sharing the secret key among communicating parties in a secure manner using quantum theory. Besides, a bitwise operator is combined with quantum concepts to secure the patient's sensed information in the wireless environment. Instead of mail and phone via sharing secret key, quantum theory with the bitwise operator is used here. Therefore, it is not possible to hack the secret key of communication. The body sensor's constrained assets as far as battery life, memory, and computational limit are considered for showing the efficiency of the proposed security framework. Based on experimental results, it is proven that the proposed algorithm EBB84QCP provides high secure key distribution method without direct sharing the secret key and it used the quantum mechanism and bitwise operator for generating and distributing secret key value to communicating parties for sensitive information sharing in the wireless body sensor networks. [ABSTRACT FROM AUTHOR]

Quantum key distribution (QKD) is a revolutionary cryptography response to the rapidly growing cyberattacks threat posed by quantum computing. Yet, the roadblock limiting the vast expanse of secure quantum communication is the exponential decay of the transmitted quantum signal with the distance. Today's quantum cryptography is trying to solve this problem by focusing on quantum repeaters. However, efficient and secure quantum repetition at sufficient distances is still far beyond modern technology. Here, we shift the paradigm and build the long-distance security of the QKD upon the quantum foundations of the Second Law of Thermodynamics and end-to-end physical oversight over the transmitted optical quantum states. Our approach enables us to realize quantum states' repetition by optical amplifiers keeping states' wave properties and phase coherence. The unprecedented secure distance range attainable through our approach opens the door for the development of scalable quantum-resistant communication networks of the future. [ABSTRACT FROM AUTHOR]

Continuous variable quantum cryptography has developed rapidly in recent decades, but how to verify identity in the continuous variable quantum system is still an urgent issue. To solve this problem, we propose a continuous variable quantum identification (CV-QI) protocol based on the correlation of the two-mode squeezed vacuum state and the continuous variable teleportation. The bidirectional identity verification between two participants of the communication can be achieved by the proposed CV-QI protocol. To guarantee the security, we make full use of the decoy state sequences during the whole process of the proposed CV-QI protocol. Besides, we provide the security analyses of the proposed CV-QI protocol, and analyses indicate that the security of the proposed CV-QI protocol is guaranteed. [ABSTRACT FROM AUTHOR]

Information security and identity authentication are both critical in communication. Authentication allows the receiver to receive (quantum) information and confirm the sender's identity. In 2019, Zheng and Long designed an improved version of Zhong et al. controlled quantum secure direct communication with authentication (CQSDCA) protocol, which uses the five-particle cluster state and an exclusive-or (XOR) operation. This protocol ensures data transfer security by including authentication and control phases. However, it was found in this study that the improved CQSDCA protocol has two weaknesses: (1) an external attacker may impersonate the sender, and (2) an external attacker could modify the messages sent by the sender. To solve these problems, we designed a protocol that uses part of a pre-shared key to determine particle sequence ordering and utilizes the computation of hash functions for identity authentication. These improvements prevent modification and impersonation attacks by an external attacker, thus improving the security of the CQSDCA protocol. [ABSTRACT FROM AUTHOR]

This paper proposes a cheating identifiable (t, m) threshold quantum secret sharing scheme based on the d-dimensional Bell state and single-qudit unitary operations. In the proposed protocol, the dealer generates a Bell state and transmits the first particle to the participants; then, t out of m participants perform the unitary operations on the Bell states' particle. The dealer shares both classical and quantum information. The Bell states are used to reconstruct the secret and identify the malicious behavior of a dishonest participant. After verifying any eavesdropping and dishonest participant, the dealer transforms a unitary operation on the second particle of the Bell state and sends it to the participant to regenerate the secret. The protocol is reliable in identifying dishonest participants and negating any eavesdropping. The proposed protocol is more adaptable, effective, and practical than the relevant quantum secret sharing schemes. [ABSTRACT FROM AUTHOR]

In this paper, we utilize the potential offered by multidimensional separable states (MSS) for secure and simultaneous distributions of keys in a layered network. We present protocols for both quantum and semi-quantum key distribution and discuss their robustness against various eavesdropping strategies. We provide a procedure to identify the requisite resource states to generalize these protocols for arbitrary layered networks. Finally, we study the interrelation between the local dimensionalities of states and achievable key rates in a given layer. These proposals are realizable with current technology, thanks to the employment of MSS and many advances in the generation, manipulation, and measurement of higher-dimensional orbital angular momentum states of light. [ABSTRACT FROM AUTHOR]

Classical microprocessors operate on irreversible gates, that, when combined with AND, half-adder and full-adder operations, execute complex tasks such as multiplication of integers. We introduce parity versions of all components of a multiplication circuit. The parity gates are reversible quantum gates based on the recently introduced parity transformation and build on ground-space encoding of the corresponding gate logic. Using a quantum optimization heuristic, e.g., an adiabatic quantum computing protocol, allows one to quantum mechanically reverse the process of multiplication and thus factor integers, which has applications in cryptography. Our parity approach builds on nearest-neighbor constraints equipped with local fields, able to encode the logic of a binary multiplication circuit in a modular and scalable way. The authors present a method of prime factorization using quantum logic, based on parity-based gates. Using this approach, they formulate factorization as an optimization problem and show a quadratic advantage in the number of qubits required over other standard representations. [ABSTRACT FROM AUTHOR]

Quantum hash function is an important area of interest in the field of quantum cryptography. Quantum hash function based on controlled alternate quantum walk is a mainstream branch of quantum hash functions by virtue of high efficiency and flexibility. In recent development of this kind of schemes, evolution operators determined by an input message depend on not only coin operators, but also direction-determine transforms, which usually are hard to extend. Moreover, the existing works ignore the fact that improper choice of initial parameters may cause some periodic quantum walks, and further collisions. In this paper, we propose a new quantum hash function scheme based on controlled alternate lively quantum walks with variable hash size and provide the selection criteria for coin operators. Specifically, each bit of an input message determines the magnitude of an additional long-range hop for the lively quantum walks. Statistical analysis results show excellent performance in the aspect of collision resistance, message sensitivity, diffusion and confusion property, and uniform distribution property. Our study demonstrates that a fixed coin operator, along with different shift operators, can effectively work on the design of a quantum hash function based on controlled alternate quantum walks, and shed new light on this field of quantum cryptography. [ABSTRACT FROM AUTHOR]

We investigate the security assumptions behind three public-key quantum money schemes. Aaronson and Christiano proposed a scheme based on hidden subspaces of the vector space F 2 n in 2012. It was conjectured by Pena et al. (IACR international workshop on public-key cryptography, pp 194–213. Springer, 2015) that the hard problem underlying the scheme can be solved in quasi-polynomial time. We confirm this conjecture, and hence prove that the scheme is insecure, by giving a polynomial time quantum algorithm for the underlying problem. Our algorithm is based on computing the Zariski tangent space of a random point in the hidden subspace. Zhandry (Quantum lightning never strikes the same state twice 11, 2017. ) proposed a scheme based on multivariate hash functions. We prove that Zhandry’s scheme is insecure by giving a polynomial time quantum algorithm for cloning a money state with high probability. Our algorithm uses the verification circuit of the scheme to produce a banknote from a given serial number. Kane et al. (Quantum money from quaternion algebras, 2021. ) proposed a scheme based on quaternion algebras. The underlying hard problem in their scheme is cloning a quantum state that represents an eigenvector of a set of Hecke operators. We give a polynomial time quantum reduction from this hard problem to a linear algebra problem. Although our reduction does not break this scheme, the latter problem is much easier to understand, and we hope that our reduction opens new avenues to future cryptanalyses of the scheme. [ABSTRACT FROM AUTHOR]