Quantum Cryptographic Protocols Research Articles

Subcarrier wave continuous-variable quantum key distribution with Gaussian modulation: composable security analysis

In this paper, we continue the study of the quantum cryptographic GG02 protocol, performed using the approach based on the subcarrier waves. We modify the scheme via heterodyne detection and perform security analysis for the full trusted hardware noise model in the presence of collective attacks with finite-key effects. It is shown that the system can potentially distribute the key even if the level of losses in the channel is above 9 dB. This result is consistent with the general technical level and comply with modern standards of practical CV-QKD systems. Finally, the system under consideration fully meets the criterion of composability.

Entanglement based six-state quantum cryptography protocol: exact proof of security

A novel quantum key distribution (QKD) protocol is proposed, which uses six states of three states in two bases. The protocol provides a greater range of key distribution compared to known QKD protocols. The protocol has an accurate proof of secrecy based on fundamental entropy uncertainty relations, the use of which is possible with the entanglement version of the protocol. The implementation of the protocol does not require adjustment of the polarization state at the output of the communication line, since the receiving side does not use active polarization-sensitive elements—phase modulators, which virtually excludes active probing of the active elements of the system.

Privacy and correctness trade-offs for information-theoretically secure quantum homomorphic encryption

Quantum homomorphic encryption, which allows computation by a server directly on encrypted data, is a fundamental primitive out of which more complex quantum cryptography protocols can be built. For such constructions to be possible, quantum homomorphic encryption must satisfy two privacy properties: data privacy which ensures that the input data is private from the server, and circuit privacy which ensures that the ciphertext after the computation does not reveal any additional information about the circuit used to perform it, beyond the output of the computation itself. While circuit privacy is well-studied in classical cryptography and many homomorphic encryption schemes can be equipped with it, its quantum analogue has received little attention. Here we establish a definition of circuit privacy for quantum homomorphic encryption with information-theoretic security. Furthermore, we reduce quantum oblivious transfer to quantum homomorphic encryption. By using this reduction, our work unravels fundamental trade-offs between circuit privacy, data privacy and correctness for a broad family of quantum homomorphic encryption protocols, including schemes that allow only the computation of Clifford circuits.

ANALYSIS OF QUANTUM SECURE DIRECT COMMUNICATION PROTOCOLS

The development of modern computer technologies endangers the confidentiality of information, which is usually ensured by traditional cryptographic means. This circumstance forces us to look for new methods of protection. In view of modern trends, quantum cryptography methods can become such alternatives, which allow solving a number of important cryptographic problems, for which the impossibility of solving using only classical (that is, non-quantum) communication has been proven. Quantum cryptography is a branch of quantum informatics that studies methods of protecting information by using quantum carriers. The possibility of such protection is ensured by the fundamental laws of quantum mechanics. One of the promising directions of quantum cryptography is Quantum Secure Direct Communication (QSDC) that offers secure communication without any shared key. A characteristic feature of this method is the absence of cryptographic transformations, accordingly, there is no key distribution problem. The purpose of this work is a general overview of quantum cryptography protocols, finding their weak points for further development and improvement, as well as identifying vulnerabilities to different attacks. The article analyzes new methods and protocols, as well as presents their advantages and disadvantages. Based on partial generalizations of theoretical provisions and practical achievements in the field of quantum cryptography, a generalized classification was developed. By comparing various factors of the protocols, and their resistance to certain cyberattacks, we have the opportunity to identify several problems in this field and expand the possibilities for choosing appropriate methods for building modern quantum information protection systems. In accordance with this, conclusions were presented regarding the use of protocols and increasing the level of their effectiveness.

Quantum Authentication Using Double Teleportation

A process involving quantum teleportation to teleport a state to two parties in superposition is presented. Then, the process is applied to cryptography. Concretely in this work, we present the process of cryptography authentication using an undefined qubit state and the double quantum teleportation presented previously. Since quantum cryptography protocols are susceptible of eavesdropping, then such a process is considered through an eavesdropper trying to steal the information to supplant the user of authentication in order to quantify certain limits of applicability.

Multiparty blind quantum computation protocol with deterministic mutual identity authentication

Blind quantum computation (BQC) studies the problem of how a client with limited quantum computation power delegates a computing task to a quantum server while keeping his input, output and algorithm private. To resist attacks from the lack of identity authentication in BQC protocols, we propose a multiparty BQC protocol with deterministic mutual identity authentication. For concreteness, a variant of measurement-device-independent quantum key distribution (MDI-QKD) is first presented, and based on this, a method of deterministically generating the authentication keys of the registered client and the designated server is presented in the registration phase. Then a deterministic mutual identity authentication protocol is proposed to authenticate the identities of the registered client and the designated server by using the variant of MDI-QKD. Finally, in the blind quantum computation phase, the registered client can delegate a computing task to the designated server. Compared with existing BQC protocols with mutual identity authentication, our proposal works in a deterministic and efficient way. Furthermore, the proposed mutual identity authentication method can be applied in other quantum cryptography protocols, thus providing a valuable way for the construction of multiparty quantum communication protocols with identity authentication.

MACROBITS, a teaching tool for quantum cryptography

One amazing characteristic of quantum algorithms is how they can deliver results with 100% certainty despite their structure being based on the probabilistic interpretation of quantum mechanics. This type of algorithm requires a different way of thinking and sets a challenge for science educators. A routine to emulate quantum cryptography protocols for high school students is proposed in this work. The educational procedure uses a tool we have developed and called MACROBIT as a mean to mimic algorithms of quantum key distribution. The MACROBITS are useful to illustrate quantum mechanics concepts such as superposition, change of basis and quantum measurement.

Development of Quantum Protocol Modification CSLOE–2022, Increasing the Cryptographic Strength of Classical Quantum Protocol BB84

Quantum cryptography protocols make it possible not only to ensure the protection of data transmitted in a communication channel from unauthorized access by intruders, but also to detect the existence of any attempted interception. This scientific direction is currently relevant, since it is related to the problem of security and data protection in current information and communication networks. The article is devoted to quantum cryptography; it describes the development of quantum protocols as quantum key distribution systems. Grounded on the laws of quantum mechanics, the elaboration of modifications of secure data transfer protocols is shown. The authors considered the best-known protocol to be BB84 of quantum key distribution; a more modern modification of this protocol is BB84 Info-Z. Comparative analysis of these has also been carried out. It has been established that the BB84-Info-Z quantum protocol works more efficiently than BB84 since its lower error threshold allows the interceptor to obtain much less information about the secret key. The authors put forward a new idea to improve the BB84 protocol (which has been quite outdated for almost 40 years), due to the increase in modern requirements for quantum cryptography protocols. The modification is called CSLOE-2022. It enables significant intensification of cryptographic strength and the entanglement degree of the interceptor (cryptanalyst), which greatly complicates the very possibility of intercepting information. The ultimate goal of the CSLOE-2022 modification is to complicate the eavesdropping process so much that it can be considered completely useless for an attacker in terms of wasting time and resources. The modification allows exceeding the known speed limit of key generation without repeaters since it uses two sources, the phases of which, in addition to the hundreds of kilometers of fiber between them, are very difficult to stabilize. Comparison of the protocols by working distance showed that for BB84, this distance does not exceed 70 km; for BB84-Info-Z it is similar, at no more than 70 km, and the modification of CSLOE-2022 proposed by the authors theoretically allows increasing the working distance of the quantum protocol to 511 km (7.3 times).

Anonymous blind quantum computation protocol fordistributed quantum networks

<p indent="0mm">Quantum cyber security aims to examine the communication and computation of security within a distributed quantum network. Two primary security concerns, privacy and anonymity, are typically investigated in quantum computational tasks. Therefore, this study proposes a state-of-the-art, single-server, multi-user anonymous blind quantum computation protocol, wherein the anonymous entanglement shared between the server and user is utilized as a quantum resource for blind quantum computation tasks. The anonymity, blindness, and security analyses demonstrated that the proposed protocol can perform blind quantum computation tasks while maintaining the confidentiality of the user identity. Compared with conventional blind quantum computation protocols, this protocol provides additional security for blind quantum computing and serves as a novel design idea for anonymous quantum cryptography protocols.

Classically verifiable quantum advantage from a computational Bell test

Existing experimental demonstrations of quantum computational advantage have had the limitation that verifying the correctness of the quantum device requires exponentially costly classical computations. Here we propose and analyse an interactive protocol for demonstrating quantum computational advantage, which is efficiently classically verifiable. Our protocol relies on a class of cryptographic tools called trapdoor claw-free functions. Although this type of function has been applied to quantum advantage protocols before, our protocol employs a surprising connection to Bell’s inequality to avoid the need for a demanding cryptographic property called the adaptive hardcore bit, while maintaining essentially no increase in the quantum circuit complexity and no extra assumptions. Leveraging the relaxed cryptographic requirements of the protocol, we present two trapdoor claw-free function constructions, based on Rabin’s function and the Diffie–Hellman problem, which have not been used in this context before. We also present two independent innovations that improve the efficiency of our implementation and can be applied to other quantum cryptographic protocols. First, we give a scheme to discard so-called garbage bits, removing the need for reversibility in the quantum circuits. Second, we show a natural way of performing postselection that reduces the fidelity needed to demonstrate quantum advantage. Combining these results, we describe a blueprint for implementing our protocol on Rydberg atom-based quantum devices, using hardware-native operations that have already been demonstrated experimentally.

Theory of Communication Efficient Quantum Secret Sharing

A <inline-formula> <tex-math notation="LaTeX">$((k,n))$ </tex-math></inline-formula> quantum threshold secret sharing (QTS) scheme is a quantum cryptographic protocol for sharing a quantum secret among <inline-formula> <tex-math notation="LaTeX">$n$ </tex-math></inline-formula> parties such that the secret can be recovered by any <inline-formula> <tex-math notation="LaTeX">$k$ </tex-math></inline-formula> or more parties while <inline-formula> <tex-math notation="LaTeX">$k-1$ </tex-math></inline-formula> or fewer parties have no information about the secret. Despite extensive research on these schemes, there has been very little study on optimizing the quantum communication cost during recovery. Recently, we initiated the study of communication efficient quantum threshold secret sharing (CE-QTS) schemes. These schemes reduce the communication complexity in QTS schemes by accessing <inline-formula> <tex-math notation="LaTeX">$d&gt;k$ </tex-math></inline-formula> parties for recovery; here <inline-formula> <tex-math notation="LaTeX">$d$ </tex-math></inline-formula> is fixed ahead of encoding the secret. In contrast to the standard QTS schemes which require <inline-formula> <tex-math notation="LaTeX">$k$ </tex-math></inline-formula> qudits for recovering each qudit in the secret, these schemes have a lower communication cost of <inline-formula> <tex-math notation="LaTeX">$\frac {d}{d-k+1}$ </tex-math></inline-formula>. In this paper, we further develop the theory of communication efficient quantum threshold schemes. Here, we propose universal CE-QTS schemes which reduce the communication cost for all <inline-formula> <tex-math notation="LaTeX">$d&gt;k$ </tex-math></inline-formula> simultaneously. We provide a framework based on ramp quantum secret sharing to construct CE-QTS and universal CE-QTS schemes. We give another construction for universal CE-QTS schemes based on Staircase codes. We derived a lower bound on communication complexity and show that our constructions are optimal. Finally, an information theoretic model is developed to analyse CE-QTS schemes and the lower bound on communication complexity is proved again using this model.

Progress toward practical quantum cryptanalysis by variational quantum cloning

Cryptanalysis of quantum cryptographic systems generally involves finding optimal adversarial attack strategies on the underlying protocols. The core principle of modeling quantum attacks often reduces to the ability of the adversary to clone unknown quantum states and to extract thereby meaningful secret information. Explicit optimal attack strategies typically require high computational resources due to large circuit depths or, in many cases, are unknown. Here we introduce variational quantum cloning (VarQlone), a cryptanalysis algorithm based on quantum machine learning, which allows an adversary to obtain optimal approximate cloning strategies with short depth quantum circuits, trained using hybrid classical-quantum techniques. The algorithm contains operationally meaningful cost functions with theoretical guarantees, quantum circuit structure learning and gradient-descent-based optimization. Our approach enables the end-to-end discovery of hardware-efficient quantum circuits to clone specific families of quantum states, which we demonstrate in an implementation on the Rigetti Aspen quantum hardware. We connect these results to quantum cryptographic primitives and derive explicit attacks facilitated by VarQlone. We expect that quantum machine learning will serve as a resource for improving attacks on current and future quantum cryptographic protocols.

Distance Enhancement of Quantum Cryptography through MANET

In the modern technology world, the cryptographic techniques are plays a major role. There are so many modern cryptographic algorithms are used to secure information through message transformation. Quantum cryptography evolved from the merging of physics and cryptography to reduce the threat that encryption encounters. It is one of the emerging fields in the computer technology. The primary objective of quantum cryptography research is to develop cryptographic algorithms and protocols that are resistant to quantum computer attacks and increase the communication distance. The various quantum cryptography protocols are demonstrated, as well as how this technology has led to the establishment of secure communication between sender and the receiver through using of MANET. We will look at the properties of quantum cryptography and the benefits of MANET it can provide in the future internet. One of the best ways for increasing the distance of message transmission over the internet is to use MANET in the field of quantum cryptography. An Ad hoc on demand distance vector (AODV) is a routing protocol for Mobile Ad hoc networks

Quantum teleportation with one classical bit

Quantum teleportation allows one to transmit an arbitrary qubit from point A to point B using a pair of (pre-shared) entangled qubits and classical bits of information. The conventional protocol for teleportation uses two bits of classical information and assumes that the sender has access to only one copy of the arbitrary qubit to be sent. Here, we ask whether we can do better than two bits of classical information if the sender has access to multiple copies of the qubit to be teleported. We place no restrictions on the qubit states. Consequently, we propose a modified quantum teleportation protocol that allows Alice to reset the state of the entangled pair to its initial state using only local operations. As a result, the proposed teleportation protocol requires the transmission of only one classical bit with a probability greater than one-half. This has implications for efficient quantum communications and the security of quantum cryptographic protocols based on quantum entanglement.

Entanglement concentration protocols for quantum entangled states

Noise in the channel affects the security of cryptography protocols. The obvious solution for quantum protocols is to estimate the transformation of quantum states caused by the noise. Cluster states are the basic structures of quantum cryptography protocols, which are transmitted through the lossy quantum channel during the procedure of the protocols. The entanglement of the cluster states is extremely fragile and easy to be inflected by inevitable interaction with the environment. To ensure the fidelity of cluster states, the entanglement of the states must be concentrated after the transmission. We propose four protocols to concentrate the entanglement of five-photon linear cluster states by linear optics, in two of which only three parties should perform the local POVM operations. All the protocols reach the maximum of successful probability, and furthermore they are implemented by the linear optics alone. The simulation results depict that lots of five-photon linear cluster states could be concentrated via our protocols, and those protocols are robust against the accuracy of the linear optics. Hence, our protocols are valuable in many fields of quantum information and quantum cryptography.

Private Computation of Phylogenetic Trees Based on Quantum Technologies

Individuals&#x2019; privacy and legal regulations demand genomic data be handled and studied with highly secure privacy-preserving techniques. In this work, we propose a feasible Secure Multiparty Computation (SMC) system assisted with quantum cryptographic protocols that is designed to compute a phylogenetic tree from a set of private genome sequences. This system significantly improves the privacy and security of the computation thanks to three quantum cryptographic protocols that provide enhanced security against quantum computer attacks. This system adapts several distance-based methods (Unweighted Pair Group Method with Arithmetic mean, Neighbour-Joining, Fitch-Margoliash) into a private setting where the sequences owned by each party are not disclosed to the other members present in the protocol. We theoretically evaluate the performance and privacy guarantees of the system through a complexity analysis and security proof and give an extensive explanation about the implementation details and cryptographic protocols. We also implement a quantum-assisted secure phylogenetic tree computation based on the Libscapi implementation of the Yao, the PHYLIP library and simulated keys of two quantum systems: Quantum Oblivious Key Distribution and Quantum Key Distribution. This demonstrates its effectiveness and practicality. We benchmark this implementation against a classical-only solution and we conclude that both approaches render similar execution times, the only difference being the time overhead taken by the oblivious key management system of the quantum-assisted approach.

Review on entropic uncertainty relations

The Heisenberg uncertainty principle is one of the characteristics of quantum mechanics. With the vigorous development of quantum information theory, uncertain relations have gradually played an important role in it. In particular, in order to solved the shortcomings of the concept in the initial formulation of the uncertainty principle, we brought entropy into the uncertainty relation, after that, the entropic uncertainty relation has exploited the advantages to the full in various applications. As we all know the entropic uncertainty relation has became the core element of the security analysis of almost all quantum cryptographic protocols. This review mainly introduces development history and latest progress of uncertain relations. After Heisenberg's argument that incompatible measurement results are impossible to predict, many scholars, inspired by this viewpoint, have made further relevant investigations. They combined the quantum correlation between the observable object and its environment, and carried out various generalizations of the uncertainty relation to obtain more general formulas. In addition, it also focuses on the entropy uncertainty relationship and quantum-memory-assisted entropic uncertainty relation, and the dynamic characteristics of uncertainty in some physical systems. Finally, various applications of the entropy uncertainty relationship in the field of quantum information are discussed, from randomnesss to wave-particle duality to quantum key distribution.

Current Status and Future Development of Quantum Cryptographic Protocols

Quantum computing has the capability of parallel computing and is superior to classical computing in solving some specific problems. Once a large-scale quantum computer is developed, the security of classical cryptographic algorithms and protocols, which is based on the assumption of computational complexity, will be severely challenged. Quantum cryptography is a new cryptosystem; its security is based on the principles of quantum mechanics, and can resist the attack of quantum computing. This paper focuses on the nearly 40 years development of quantum cryptographic protocols, including quantum key distribution (QKD), quantum secure direct communication, quantum secret sharing, quantum identity authentication, two-party secure computation, and quantum private query, and summarizes the problems in the process of development. The analysis shows that the quantum cryptographic protocols are in an unbalanced state: QKD is far ahead of other protocols and other protocols are difficult to achieve breakthroughs. In the future, practical quantum protocols for digital signature and two-party secure computation are core issues that needs to be addressed urgently. Therefore, research on quantum and post-quantum cryptography should be conducted synchronously, cross-over study and talent cultivation for the quantum science and cryptography disciplines should be strengthened, and the examination and evaluation mechanism of relevant basic research needs to be optimized.

Modeling and Verification of Aircraft Takeoff Through Novel Quantum Nets

The formal modeling and verification of aircraft takeoff is a challenge because it is a complex safety-critical operation. The task of aircraft takeoff is distributed amongst various computer-based controllers, however, with the growing malicious threats a secure communication between aircraft and controllers becomes highly important. This research serves as a starting point for integration of BB84 quantum protocol with petri nets for secure modeling and verification of takeoff procedure. The integrated model combines the BB84 quantum cryptographic protocol with powerful verification tool support offered by petri nets. To model certain important properties of BB84, a new variant of petri nets coined as Quantum Nets are proposed by defining their mathematical foundations and overall system dynamics, furthermore, some important system properties are also abstractly defined. The proposed Quantum Nets are then applied for modeling of aircraft takeoff process by defining three quantum nets: namely aircraft, runway controller and gate controller. For authentication between quantum nets, the use of external places and transitions is demonstrated to describe the encryption-decryption process of qubits stream. Finally, the developed takeoff quantum network is verified through simulation offered by colored petri-net (CPN) Tools. Moreover, reachability tree (RT) analysis is also performed to have greater confidence in feasibility and correctness of the proposed aircraft takeoff model through the Quantum Nets.

Cloud Data Security through BB84 Protocol and Genetic Algorithm

In the current digitalized world, cloud computing becomes a feasible solution for the virtualization of cloud computing resources. Though cloud computing has many advantages to outsourcing an organization’s information, but the strong security is the main aspect of cloud computing. Identity authentication theft becomes a vital part of the protection of cloud computing data. In this process, the intruders violate the security protocols and perform attacks on the organizations or user’s data. The situation of cloud data disclosure leads to the cloud user feeling insecure while using the cloud platform. The different traditional cryptographic techniques are not able to stop such kinds of attacks. BB84 protocol is the first quantum cryptography protocol developed by Bennett and Brassard in the year 1984. In the present work, three ways BB84GA security systems have been demonstrated using trusted cryptographic techniques like an attribute-based authentication system, BB84 protocol, and genetic algorithm. Firstly, attribute-based authentication is used for identity-based access control and thereafter BB84 protocol is used for quantum key distribution between both parties and later the concept of genetic algorithm is applied for encryption/decryption of sensitive information across the private/public clouds. The proposed concept of involvement of hybrid algorithms is highly secure and technologically feasible. It is a unique algorithm which may be used to minimize the security threats over the clouds. The computed results are presented in the form of tables and graphs.