Quantum Oblivious Transfer with Reusable Bell State

In cryptography,oblivious transfer(OT)is an important multiparty cryptographic primitive and protocol,that is suitable for many upperlayer applications,such as secure computation,remote coin-flipping,electrical contract signing and exchanging secrets simultaneously.However,some nogo theorems have been established,indicating that one-out-of-two quantum oblivious transfer(QOT)protocols with unconditional security are impossible.Fortunately,some one-out-of-two QOT protocols using the concept of Crepeau’s reduction have been demonstrated not to conform to Lo’s no-go theorem,but these protocols require more quantum resources to generate classical keys using all-or-nothing QOT to construct one-out-of-two QOT.This paper proposes a novel and efficient one-out-of-two QOT which uses quantum resources directly instead of wasting unnecessary resources to generate classical keys.The proposed protocol is not covered by Lo’s no-go theorem,and it is able to check the sender’s loyalty and avoid the attack from the receiver.Moreover,the entangled state of the proposed protocol is reusable,so it can provide more services for the participants when necessary.Compared with otherQOT protocols,the proposed protocol is more secure,efficient,and flexible,which not only can prevent external and internal attacks,but also reduce the required resources and resource distribution time.

Controlled quantum teleportation with Bell states

We propose a new scheme for controlled quantum teleportation with Bell states in which classical keys for controllers＇ portion are used. We also discuss the security of the proposed scheme and show that it can satisfy the requirements for controlled quantum teleportation. The comparison between this scheme and the previous ones shows that it is more economical and efficient.

Dynamic quantum secret sharing protocol based on two-particle transform of Bell states

To solve the problems of updating sub-secrets or secrets as well as adding or deleting agents in the quantum secret sharing protocol, we propose a two-particle transform of Bell states, and consequently present a novel dynamic quantum secret sharing protocol. The new protocol can not only resist some typical attacks, but also be more efficient than the existing protocols. Furthermore, we take advantage of the protocol to establish the dynamic secret sharing of a quantum state protocol for two-particle maximum entangled states.

Multiparty Quantum Secret Sharing Using Two-Photon Three-Dimensional Bell States

We present a two-photon three-dimensional multiparty quantum secret sharing scheme.The secret messagesare encoded by performing local operations.This is different from those quantum secret sharing protocols that all sharersmust make a state measurement.The merit of our protocol is the high capacity.

A novel quantum information hiding protocol based on entanglement swapping of high-level Bell states

Using entanglement swapping of high-level Bell states, we first derive a covert layer between the secret message and the possible output results of the entanglement swapping between any two generalized Bell states, and then propose a novel high-efficiency quantum information hiding protocol based on the covert layer. In the proposed scheme, a covert channel can be built up under the cover of a high-level quantum secure direct communication （QSDC） channel for securely transmitting secret messages without consuming any auxiliary quantum state or any extra communication resource. It is shown that this protocol not only has a high embedding efficiency but also achieves a good imperceptibility as well as a high security.

Fault tolerant deterministic secure quantum communication using logical Bell states against collective noise

This study proposes two novel fault tolerant deterministic secure quantum communication （DSQC） schemes resistant to collective noise using logical Bell states. Either DSQC scheme is constructed based on a new coding function, which is designed by exploiting the property of the corresponding logical Bell states immune to collective-dephasing noise and collective-rotation noise, respectively. The secret message can be encoded by two simple unitary operations and decoded by merely performing Bell measurements, which can make the proposed scheme more convenient in practical applications. Moreover, the strategy of one-step quanta transmission, together with the technique of decoy logical qubits checking not only reduces the influence of other noise existing in a quantum channel, but also guarantees the security of the communication between two legitimate users. The final analysis shows that the proposed schemes are feasible and robust against various well-known attacks over the collective noise channel.

Anti-Noise Quantum Network Coding Protocol Based on Bell States and Butterfly Network Model

How to establish a secure and efficient quantum network coding algorithm isone of important research topics of quantum secure communications. Based on thebutterfly network model and the characteristics of easy preparation of Bell states, a novelanti-noise quantum network coding protocol is proposed in this paper. The new protocolencodes and transmits classical information by virtue of Bell states. It can guarantee thetransparency of the intermediate nodes during information, so that the eavesdropper Evedisables to get any information even if he intercepts the transmitted quantum states. Inview of the inevitability of quantum noise in quantum channel used, this paper analyzesthe influence of four kinds of noises on the new protocol in detail further, and verifies theefficiency of the protocol under different noise by mathematical calculation and analysis.In addition, based on the detailed mathematical analysis, the protocol has functioned wellnot only on improving the efficiency of information transmission, throughput and linkutilization in the quantum network, but also on enhancing reliability and antieavesdroppingattacks.

A novel scheme of hybrid entanglement swapping and teleportation using cavity QED in the small and large detuning regimes and quasi-Bell state measurement method

We outline a scheme for entanglement swapping based on cavity QED as well as quasi-Bell state measurement(quasiBSM) methods. The atom–field interaction in the cavity QED method is performed in small and large detuning regimes.We assume two atoms are initially entangled together and, distinctly two cavities are prepared in an entangled coherent–coherent state. In this scheme, we want to transform entanglement to the atom-field system. It is observed that, the fidelities of the swapped entangled state in the quasi-BSM method can be compatible with those obtained in the small and large detuning regimes in the cavity QED method(the condition of this compatibility will be discussed). In addition, in the large detuning regime, the swapped entangled state is obtained by detecting and quasi-BSM approaches. In the continuation,by making use of the atom–field entangled state obtained in both approaches in a large detuning regime, we show that the atomic as well as field states teleportation with complete fidelity can be achieved.

Bell States and Two-Qubit Logic Gate with Superconducting Charge Qubits Coupling to a Nanomechanical Resonator

We propose a scheme for generating Bell states involving two SQUID-based charge qubits by coupling themto a nanomechanical resonator.We also show that it is possible to implement a two-qubit logic gate between the twocharge qubits by choosing carefully the interaction time.

Entropy of Field Interacting With Two Atoms in Bell State

In this paper, we investigate entropy properties of the single-mode coherent optical field interacting with the two two-level atoms initially in one of the four Bell states. It is found that the different initial states of the two atoms lead to different evolutions of field entropy and the intensity of the field plays an important role for the evolution properties of field entropy.

Indistinguishability of orthogonal time-separated bell states

This paper proves that it is impossible to identify orthogonally time-separated Bell states. If two qubits of a Bell state interact with the measurement apparatus at different time, any attempt to identify this state will disturb it.

Perfect Quantum Teleportation via Bell States

Quantum mechanics shows superiority than classical mechanics in many aspects and quantum entanglement plays an essential role in information processing and some computational tasks such as quantum teleportation(QT).QT was proposed to transmit the unknown states,in which EPR pairs,the entangled states,can be used as quantum channels.In this paper,we present two simple schemes for teleporting a product state of two arbitrary single-particle and an arbitrary two-particle pure entangled state respectively.Alice and Bob have shared an entangle state.Two Bell states are used as quantum channels.Then after Alice measuring her qubits and informing Bob her measurement results,Bob can perfectly reconstruct the original state by performing corresponding unitary operators on his qubits.It shown that a product state of two arbitrary single-particle and an arbitrary two-particle pure entangled state can be teleported perfectly,i.e.the success probabilities of our schemes are both 1.

Quantum States Transfer by Analogous Bell States

Transmitting quantum states by channels of analogous Bell states is studied in this paper. We analyze the transmitting process. constructed the probabilitic unitary operator, and gain the largest successful transfer quantum state probability.

Quantum Secure Direct Communication Protocol with Mutual Authentication Based on Single Photons and Bell States

Quantum secure direct communication(QSDC)can transmit secret messages directly from one user to another without first establishing a shared secret key,which is different from quantum key distribution.In this paper,we propose a novel quantum secure direct communication protocol based on signal photons and Bell states.Before the execution of the proposed protocol,two participants Alice and Bob exchange their corresponding identity IDA and IDB through quantum key distribution and keep them secret,respectively.Then the message sender,Alice,encodes each secret message bit into two single photons(|01>or|10>)or a Bell state(1|φ^(+)>=1/√2(|0>|-|1>1>)),and composes an ordered secret message sequence.To insure the security of communication,Alice also prepares the decoy photons and inserts them into secret message sequence on the basis of the values of IDA and IDB.By the secret identity IDA and IDB,both sides of the communication can check eavesdropping and identify each other.The proposed protocol not only completes secure direct communication,but also realizes the mutual authentication.The security analysis of the proposed protocol is presented in the paper.The analysis results show that this protocol is secure against some common attacks,and no secret message leaks even if the messages are broken.Compared with the two-way QSDC protocols,the presented protocol is a one-way quantum communication protocol which has the immunity to Trojan horse attack.Furthermore,our proposed protocol can be realized without quantum memory.

记忆泡利信道下Bell态的几何失协

几何失协是度量量子关联的一种重要方法.通过引入记忆参数,使得泡利噪声具有记忆性,此时噪声被定义为记忆泡利噪声.依据不同记忆泡利信道的噪声参数,讨论xz退相位噪声、去极化噪声、双泡利噪声以及3种翻转噪声下Bell态的几何失协,得到Bell态的几何失协与噪声参数之间的关系,并且分析记忆参数对几何失协的影响.结果表明,在记忆泡利信道下Bell态的几何失协受到噪声影响的程度更小,即记忆泡利信道可有效增强噪声影响下Bell态几何失协的稳定性.这表明记忆泡利信道可以捕获更多的信息,有利于节约量子资源.

High-efficiency quantum steganography based on the tensor product of Bell states

In this paper,we first propose a hidden rule among the secure message,the initial tensor product of two Bell states and the final tensor product when respectively applying local unitary transformations to the first particle of the two initial Bell states,and then present a high-efficiency quantum steganography protocol under the control of the hidden rule.In the proposed quantum steganography scheme,a hidden channel is established to transfer a secret message within any quantum secure direct communication(QSDC) scheme that is based on 2-level quantum states and unitary transformations.The secret message hiding/unhiding process is linked with the QSDC process only by unitary transformations.To accurately describe the capacity of a steganography scheme,a quantitative measure,named embedding efficiency,is introduced in this paper.The performance analysis shows that the proposed steganography scheme achieves a high efficiency as well as a good imperceptibility.Moreover,it is shown that this scheme can resist all serious attacks including the intercept-resend attack,measurement-resend attack,auxiliary particle attack and even the Denial of Service attack.To improve the efficiency of the proposed scheme,the hidden rule is extended based on the tensor product of multiple Bell states.

Quantum information splitting of a two-qubit Bell state using a four-qubit entangled state

A scheme is proposed for quantum information splitting of a two-qubit Bell state by using a four-qubit entangled state as a quantum channel. In the scenario, it is supposed that there axe three legitimate parties, say Alice, Bob and Chaxlie. Alice is the sender of quantum information. Bob and Charlie are two agents. Alice first performs GHZ state measurement and tells Bob and Chaxlie the measurement results via a classical channel. It is impossible for Bob to reconstruct the original state with local operations unless help is obtained from Chaxlie. If Chaxlie allows Bob to reconstruct the original state information, he needs to perform a single-qubit measurement and tell Bob the measurement result. Using the measurement results from Alice and Charlie, Bob can reconstruct the original state. We also consider the problem of security attacks. This protocol is considered to be secure.

Deterministic Teleportation Channel Using Bell State Measurements Only

Teleportation schemes based on probabilistic channels usually rely heavily on the implementation of high-dimensional unitary operations. Since high-dimensional unitary operations are very difficult to directly implement in physics experiments, methods are used to avoid high-dimensional unitary operations during the teleportation process. This paper describes how to construct a deterministic teleportation channel and a control channel using Bell state measurements only instead of high-dimensional unitary operations. Here, the general four-particle and five-particle class states are used as the potential quantum channel and the control channel for deterministic teleportation even without access to the relevant parameters. The results show that this scheme makes physical realization of teleportation more reasonable.

Fault-Tolerant Quantum Dialogue Without Information Leakage Based on Entanglement Swapping between Two Logical Bell States

At present, the anti-noise property and the information leakage resistant property are two great concerns for quantum dialogue(QD). In this paper, two anti-noise QD protocols without information leakage are presented by using the entanglement swapping technology for two logical Bell states. One works well over a collective-dephasing noise channel, while the other takes effect over a collective-rotation noise channel. The negative influence of noise is erased by using logical Bell states as the traveling quantum states. The problem of information leakage is avoided by swapping entanglement between two logical Bell states. In addition, only Bell state measurements are used for decoding, rather than four-qubit joint measurements.

Bell State Preparation Based on Switching Between Quantum System Models

For the preparation of any target Bell state under continuous quantum measurement, this paper proposes a method which achieves the control objective by switching between two different models or by switching between two control channels under one model. Proper control Hamiltonians are selected for the two system models, a switching strategy between the two models is designed, and the stability of the whole switching system is proved in theory. For a given target Bell state, the effectiveness of the proposed switching control strategy between different models is illustrated through simulation experiments.