Controlled Quantum Dialogue Research Articles

An Authenticated Controlled Quantum Dialogue Protocol Using Double-Linked GHZ-Like States in Cross-domain Setting

An Authenticated Controlled Quantum Dialogue Protocol Using Double-Linked GHZ-Like States in Cross-domain Setting

Controlled Quantum Dialogue with Five-Qubit Entangled States

Controlled Quantum Dialogue with Five-Qubit Entangled States

Optical designs for realization of a set of schemes for quantum cryptography

Several quantum cryptographic schemes have been proposed and realized experimentally in the past. However, even with an advancement in quantum technology and escalated interest in the designing of direct secure quantum communication schemes there are not many experimental implementations of these cryptographic schemes. In this paper, we have provided a set of optical circuits for such quantum cryptographic schemes, which have not yet been realized experimentally by modifying some of our theoretically proposed secure communication schemes. Specifically, we have proposed optical designs for the implementation of two single photon and one entangled state based controlled quantum dialogue schemes and subsequently reduced our optical designs to yield simpler designs for realizing other secure quantum communication tasks, i.e., controlled deterministic secure quantum communication, quantum dialogue, quantum secure direct communication, quantum key agreement, and quantum key distribution. We have further proposed an optical design for an entanglement swapping based deterministic secure quantum communication and its controlled counterpart.

Quantum direct communication protocols using discrete-time quantum walk

The unique features of quantum walk, such as the possibility of the walker to be in superposition ofthe position space and get entangled with the position space, provides inherent advantages that canbe captured to design highly secure quantum communication protocols. Here we propose two quan-tum direct communication protocols, a Quantum Secure Direct Communication (QSDC) protocoland a Controlled Quantum Dialogue (CQD) protocol using discrete-time quantum walk on a cycle.The proposed protocols are unconditionally secure against various attacks such as the intercept-resend attack, the denial of service attack, and the man-in-the-middle attack. Additionally, theproposed CQD protocol is shown to be unconditionally secure against an untrusted service providerand both the protocols are shown more secure against the intercept resend attack as compared tothe qubit based LM05/DL04 protocol.

Controlled quantum dialogue with authentication protocol on a basis of GHZ-like state

A controlled quantum dialogue with authentication protocol on a basis of GHZ-like state was proposed in this paper. To start with, three participants of the communication protocol generated a corresponding identity ID through quantum key distribution and it was kept secret. Controller Trent prepared the three-particle Greenberger–Home–Zeilinger-like (GHZ-like) state and shared with other two communication users Alice and Bob. Communication participants use the entangled particles in their respective hands which satisfy the nature of the classical XOR relationship for encryption, controlling and decryption of quantum messages and to verify the identities of communication users. Meanwhile, security of communication was assured by introducing decoy photons. According to analysis results, the proposed protocol can effectively not only prevent any form of eavesdropping behavior from external and internal eavesdroppers including the controller Trent, but also detect such activities. Finally, this protocol is proved to have high communication efficiency.

Fault Tolerant Controlled Quantum Dialogue with Logical Brown States Against Collective Noise

In view of the fact that the effects of channel noise are inevitable but easily ignored, we come up with two controlled quantum dialogue(CQD) protocols based on logical Brown states, which are against collective-dephasing and collective-rotation noises, respectively. Compared with existing protocols, there exist several outstanding advantages: firstly, Brown states, as the quantum resource, are the maximally entangled five-qubit states, which own stronger entanglement than GHZ states, W states and cluster states; secondly, the specific quantum circuits are designed to explain how two kinds of logical Brown states, to be strongly against collective noise, are constructed in theory; thirdly, the controller can be offline after quantum resource distribution and permission announcement such that his/her waiting time is effectively reduced; and fourthly, the security analysis manifests that our proposed protocols can not only eliminate the information leakage, but also resist against various well-known attacks, especially the dishonest controller’s attacks.

Continuous variable controlled quantum dialogue and secure multiparty quantum computation

A continuous variable (CV) controlled quantum dialogue (QD) scheme is proposed. The scheme is further modified to obtain two other protocols of (CV) secure multiparty computation. The first one of these protocols provides a solution of two-party socialist millionaire problem, while the second protocol provides a solution for a special type of multi-party socialist millionaire problem which can be viewed as a protocol for multiparty quantum private comparison. It is shown that the proposed scheme of (CV) controlled (QD) can be performed using bipartite entanglement and can be reduced to obtain several other two- and three-party cryptographic schemes in the limiting cases. The security of the proposed scheme and its advantage over corresponding discrete variable (DV) counterpart are also discussed. Specifically, the ignorance of an eavesdropper, i.e., information encoded by Alice/Bob, in the proposed scheme is shown to be more than that in the corresponding (DV) scheme, and thus the present scheme is less prone to information leakage inherent with the (DV) (QD) based schemes. It is further established that the proposed scheme can be viewed as a (CV) counterpart of quantum cryptographic switch which allows a supervisor to control the information transferred between the two legitimate parties to a continuously varying degree.

Continuous variable direct secure quantum communication using Gaussian states

Continuous variable one-way and controlled-two-way secure direct quantum communication schemes have been designed using Gaussian states. Specifically, a scheme for continuous variable quantum secure direct communication and another scheme for continuous variable controlled quantum dialogue are proposed using single-mode squeezed coherent states. The security of the proposed schemes against a set of attacks (e.g., Gaussian quantum cloning machine and intercept resend attacks) has been proved. Further, it is established that the proposed schemes do not require two-mode squeezed states which are essential for a set of existing proposals. The controlled two-way communication scheme is shown to be very general in nature as it can be reduced to schemes for various relatively simpler cryptographic tasks like controlled deterministic secure communication, quantum dialogue, quantum key distribution. In addition, it is briefly discussed that the proposed schemes can provide us tools to design quantum cryptographic solutions for several socioeconomic problems.

A Controlled Quantum Dialogue Protocol Based on Quantum Walks

In order to enable two parties to exchange their secret information equally, we propose a controlled quantum dialogue protocol based on quantum walks, which implements the equal exchange of secret information between the two parties with the help of the controller TP. The secret information is transmitted via quantum walks, by using this method, the previously required entangled particles do not need to be prepared in the initial phase, and the entangled particles can be produced spontaneously via quantum walks. Furthermore, to resist TP’s dishonest behavior, we use a hash function to verify the correctness of the secret information. The protocol analysis shows that it is safe and reliable facing some attacks, including intercept-measure-resend attack, entanglement attack, dishonest controller’s attack and participant attack. And has a slightly increasing efficiency comparing with the previous protocols. Note that the proposed protocol may be feasible because quantum walks prove to be implemented in different physical systems and experiments.

Fault tolerant controlled quantum dialogue against collective noise**Project supported by the National Natural Science Foundation of China (Grant No. 61502048), the Natural Science Foundation of Shanxi Province of China (Grant No. 201801D221159), the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi Province of China (Grant No. 2019L0470), and Youth Research Foundation of Shanxi University of Finance and

Quantum system is inevitably affected by the external environment in the real world. Two controlled quantum dialogue protocols are put forward based on logical χ-type states under collective noise environment. One is against collective-dephasing noise, while the other is against collective-rotation noise. Compared with existing protocols, there exist several outstanding advantages in our proposed protocols: Firstly, the χ-type state is utilized as quantum channels, it possesses better entanglement properties than GHZ state, W state as well as cluster state, which make it difficult to be destroyed by local operations. Secondly, two kinds of logical χ-type states are constructed by us in theory, which can be perfectly immune to the effects of collective noise. Thirdly, the controller can be offline after quantum distribution and permission announcement, without waiting for all the participants to complete the information coding. Fourthly, the security analysis illuminates that our protocols can not only be free from the information leakage, but also resist against the intercept-and-resend attack, the entanglement-and-measure attack, the modification attack, the conspiring attack, and especially the dishonest controller’s attacks.

Controlled quantum dialogue scheme based on different unspecific two-particle entangled state

In this paper, a controlled quantum dialogue (CQD) scheme based on different unspecific two-particle entangled state is proposed, in which legitimate users can exchange their secret messages according to unitary operations they chose and measurement results published by Charlie, realizing transmitting unspecific secrets by using unspecific entangled state. We insert decoy particles twice and get rid of useless secret messages carried by F particles to ensure security of the whole communication system, realizing the three-times channel detection. Compared to previous CQD protocols, the proposed scheme is proved to stand attack from third-party controller, and it is very secure.

Security loopholes in the controlled quantum dialogue robust against conspiring users protocol

Recently, a new controlled quantum dialogue (CQD) protocol which is secure against the conspiring attack from the users without the controller’s permission was put forward. However, it is found that this CQD protocol is weak against the different initial state (DIS) attack and the denial-of-service (DoS) attack from the dishonest controller. For the DIS attack, the controller prepares different initial states to eavesdrop on the users’ messages. For the DoS attack, the controller deliberately announces the wrong classical information which is used for the users to encode secret messages, and thus, one user gets the wrong message from the other user. To mend the DIS attack, a security check to the controller is added to prevent the dishonest controller from preparing the different initial states. To mend the DoS attack, a message authentication is added to prevent the dishonest controller from publishing the wrong classical information. It shows that the security check to the controller and the message authentication can effectively prevent the DIS attack and the DoS attack from the dishonest controller, respectively.

Cryptanalysis and improvement in controlled quantum dialogue using cluster states

The controlled quantum dialogue protocol which was put forward recently (Kao and Hwang in Quantum Inf Process 16(5):139, 2017) is analyzed. It shows that a dishonest controller can successfully eavesdrop on the secret messages that the two users send by the different initial state attack or he (she) can disturb communication without being detected by the denial-of-service attack. To improve these security loopholes, a new method to check eavesdropping is given. The correctness and efficiency of this method is proven.

Two authenticated quantum dialogue protocols based on three-particle entangled states

In this paper, we propose two authenticated quantum dialogue protocols based on three-particle entangled states, which are both completely secure and more efficient. The first controlled quantum dialogue protocol with authentication is creatively proposed, which is secure under not only some famous external attacks but also internal attacks, for example, the dishonest controller’s attack. This protocol has a slightly increasing efficiency and less qubit cost compared to previous protocols. Besides, we present the second authenticated quantum dialogue protocol, which has a high efficiency with 80% by integrating dense coding. This protocol can also resist various well-known attacks.

Fault‐Tolerant Controlled Quantum Dialogue Using Logical Qubit

The information leakage is a challenge in the design of Controlled quantum dialogue (CQD) protocols and the CQD protocol over noise channel has not been well researched. A CQD protocol without information leakage over an ideal channel is first proposed, where single photons are used to carrying secret information and pre-shared keys are used to authenticate identity and control information decoding for the prevention of information leakage, moreover, a novel kind of the unitary encoding operations with good property on the quantum operation discrimination are adopted to avoid active attacks from outside eavesdropper. By substituting logical qubits for single photons and constructing unitary encoding operations with the same property based on logical qubits, three fault-tolerant versions of the proposed CQD protocol are obtained, which can combat collective-dephasing, collective-rotation and all kinds of unitary collective noise, respectively. The security and efficiency analysis show the proposed protocols are appropriate for secure quantum dialogue in practice.

Controlled quantum dialogue using cluster states

This paper presents a new controlled quantum dialogue (CQD) protocol based on the cluster entangled states. The security analyses indicate that the proposed scheme is secure under not only various well-known attacks but also the collusive attack, where the participants may collude to communicate without the controller's permission. Compared to a previous CQD scheme, which is also robust against the conspiracy attack, the proposed protocol is more efficient in both the qubit efficiency and the hardware requirement.

Quantum cryptography over non-Markovian channels

A set of schemes for secure quantum communication are analyzed under the influence of non-Markovian channels. By comparing with the corresponding Markovian cases, it is seen that the average fidelity in all these schemes can be maintained for relatively longer periods of time. The effects of non-Markovian noise on a number of facets of quantum cryptography, such as quantum secure direct communication, deterministic secure quantum communication and their controlled counterparts, quantum dialogue, quantum key distribution, quantum key agreement, etc., have been extensively investigated. Specifically, a scheme for controlled quantum dialogue (CQD) is analyzed over damping, dephasing and depolarizing non-Markovian channels, and subsequently, the effect of these non-Markovian channels on the other schemes of secure quantum communication is deduced from the results obtained for CQD. The damped non-Markovian channel causes, a periodic revival in the fidelity; while fidelity is observed to be sustained under the influence of the dephasing non-Markovian channel. The depolarizing channel, as well as the other non-Markovian channels discussed here, show that the obtained average fidelity subjected to noisy environment depends on the strength of coupling between the quantum system with its surroundings and the number of rounds of quantum communication involved in a particular scheme.

Controlled quantum dialogue robust against conspiring users

This paper explores a new security problem in controlled quantum dialogue (CQD) protocols, where the communicants may try to conspire to communicate without the controller's permission. According to our survey, all the previous CQD protocols suffer from this attack. In order to resolve this problem, we also present an improvement protocol. The security analyses show that the improved scheme is secure under this and other well-known attacks.

A general method for selecting quantum channel for bidirectional controlled state teleportation and other schemes of controlled quantum communication

Recently, a large number of protocols for bidirectional controlled state teleportation (BCST) have been proposed using $n$-qubit entangled states ($n\in\{5,6,7\}$) as quantum channel. Here, we propose a general method of selecting multi-qubit $(n>4)$ quantum channels suitable for BCST and show that all the channels used in the existing protocols of BCST can be obtained using the proposed method. Further, it is shown that the quantum channels used in the existing protocols of BCST forms only a negligibly small subset of the set of all the quantum channels that can be constructed using the proposed method to implement BCST. It is also noted that all these quantum channels are also suitable for controlled bidirectional remote state preparation (CBRSP). Following the same logic, methods for selecting quantum channels for other controlled quantum communication tasks, such as controlled bidirectional joint remote state preparation (CJBRSP) and controlled quantum dialogue, are also provided.

Applications of quantum cryptographic switch: various tasks related to controlled quantum communication can be performed using Bell states and permutation of particles

Recently, several aspects of controlled quantum communication (e.g., bidirectional controlled state teleportation, controlled quantum secure direct communication, controlled quantum dialogue, etc.) have been studied using $n$-qubit ($n\geq3$) entanglement. Specially, a large number of schemes for bidirectional controlled state teleportation are proposed using $m$-qubit entanglement ($m\in\{5,6,7\}$). Here, we propose a set of protocols to illustrate that it is possible to realize all these tasks related to controlled quantum communication using only Bell states and permutation of particles (PoP). As the generation and maintenance of a Bell state is much easier than a multi-partite entanglement, the proposed strategy has a clear advantage over the existing proposals. Further, it is shown that all the schemes proposed here may be viewed as applications of the concept of quantum cryptographic switch which was recently introduced by some of us. The performances of the proposed protocols as subjected to the amplitude damping and phase damping noise on the channels are also discussed.