Abstract A new quantum network dialogue protocol is designed by using the entanglement property of the continuous-variable single-mode squeezed states. To verify the security of the channel in the protocol, Alice should send single-mode squeezed states respectively to Bob, Charlie, and etc. Then Bob, Charlie et al could encode the secret information with a specific encoding rule, insert the Gaussian random data into the encoded message and send them to Alice. They could deduce the secret information of their counterparts according to the measurement results. In addition, each communication party could dialogue with another communicator in a quantum way. The new proposed quantum network dialogue protocol based on single-mode squeezed states is much easier to implement compared with those based on the discrete-variable quantum states.
Abstract A new quantum network dialogue protocol is designed by using the entanglement property of the continuous-variable single-mode squeezed states. To verify the security of the channel in the protocol, Alice should send single-mode squeezed states respectively to Bob, Charlie, and etc. Then Bob, Charlie et al could encode the secret information with a specific encoding rule, insert the Gaussian random data into the encoded message and send them to Alice. They could deduce the secret information of their counterparts according to the measurement results. In addition, each communication party could dialogue with another communicator in a quantum way. The new proposed quantum network dialogue protocol based on single-mode squeezed states is much easier to implement compared with those based on the discrete-variable quantum states.
Quantum dialogue allows both communication parties to execute secure direct communication simultaneously and bidirectionally. In recent years, due to the possible applications of quantum communication technologies in military, finance, medicine and other fields, quantum dialogue has been widely concerned. In the year of 2017, NR Zhou et al designed a new quantum dialogue protocol by using the continuous-variable two-mode squeezed vacuum states, where the two communication parties encode their own secret information into the entangled optical modes with the translation operations and each communication party could deduce the secret information of their counterparts with the help of his or her secret information and the Bellbasis measurement results [1]. LH Gong et al devised an efficient three-party quantum dialogue protocol based on the continuous variable GHZ entangled states [2]. NR Zhou et al proposed a secure quantum dialogue protocol based on single-photons, which not only overcomes information leakage but also possesses an acceptable efficiency. M Xiao et al presented a novel quantum dialogue protocol without information leakage over the collective noise channel, where the logical qubits and four-qubit decoherence-free states were introduced to resist against collective-dephasing noise, collective-rotation noise and all kinds of unitary collective noise [4]. T Hwang et al proposed an authenticated quantum dialogue based on Bell states, allowing two communicators to perform mutual authentication and secure bidirectional communications simultaneously via public classical channels [5]. TY Ye proposed a quantum dialogue scheme by employing logical Bell states as the quantum resource to combat the collective-dephasing noise and the collective-rotation noise, which can accomplish the mutual identification and the dialogue between two participants simultaneously and securely over one kind of collective noise channels [6]. M Wang et al proposed a quantum dialogue protocol based on four-qubit entangled state, which is constructed by an EPR pair and two different single qubits through three Controlled-Not gates [7]. By using Bell measurements and the corresponding unitary operations, two users can exchange their messages simultaneously and directly without sharing any secret keys beforehand. The above protocols exploited different quantum states and involved two or three communication parties basically. These protocols cannot satisfy the practical applications of quantum dialogue in future possible quantum communication networks. Therefore, we will propose a multiparty continuous variable quantum dialogue protocol. Multiparty quantum dialogue protocol enables multiple communication parties to transmit and/or receive information at the same time. The protocol could ensure that there is no information leakage in the communication process according to the uncertainty principle and quantum non-cloning theorem.
Abstract A controlled semi-quantum dialogue protocol is proposed that uses semi-quantum cryptography and the concept of ‘control’. In this scheme, the supervisor Charlie prepares a large number of entangled photon pairs and separates them into an S A for verification and an S B for encoding. The quantum-capable party Alice and the classical communication party Bob proceed to encode on the S B sequence only after confirming the security of the channel. Finally, Alice performs measurements and announces the results to finalise the communication. This protocol ensures that secret information is exchanged between Alice and Bob only with Charlie’s permission, while Charlie has no access to the communicators’ secret information during the whole process. In terms of security, the protocol contains two strict security checks and accounts for noise, making it robust against both internal and external attacks, which greatly improves the security and reliability of the protocol. Finally, the efficiency analysis demonstrates that the protocol outperforms other existing protocols in terms of efficiency and its actual efficiency can approach the theoretical limit through optimization.
A novel scheme of controlled secure quantum dialogue by using Brown states was proposed in this paper.It this scheme,Alice,Bob and Charlie shared a five-particle Brown states.Alice made unitary operations on two particles of the Brown states to realize encoding her secret calssical message.Similarly,Bob performed corresponding unitary transformations to another two particles to encode the information that he wanted to send to Alice.Later,Charlie made Brown base states joint measurement on the Brown final state and announced the measured results.Alice and Bob deduced the opposite party′s information according to Charlie′s announced measurement results and her(his)unitary operation when encoding.They completed quantum dialogue successfully.Then the scheme′s security was discussed and a conclusion was drawn.Compared with the previous quantum dialogues,the secure quantum dialogue scheme adds the controlled party,ensures the communication security,and increases the particles number involving in the communication process and the coding efficiency.
In quantum cryptography,it is commonly established that quantum key distribution and quantum secure direct,communication work in a single direction,namely one direction communication schemes. However,quantum dialog protocol can enable two legal users exchange messages simultaneously,namely two direction communication.Most existed proposals of quantum dialog protocol are based on discrete variables, which are much more difficult to implement with today's technology,thus they are less practical than its counterpart.Based on squeezed states,a new quantum dialog scheme is proposed,information-theoretical analysis is then followed and it shows that our scheme is not only secure,but also has larger channel capacity than that of its counterpart.
In this paper, a controlled quantum dialogue (CQD) protocol based on Brown states is proposed. In the beginning, the controller Cindy creates a five-qubit Brown state as the channel and distributes it to the other two communication participants, Alice and Bob. Then, Alice and Bob can encode the secret key by performing unitary operation onto the entangled particles that Cindy sends to them. Finally, the messages can be exchanged by entanglement swapping and the results of Bell state measurement. The security analysis shows that our protocol cannot only solves the problem of information leakage, but also can effectively prevent a variety of well-known attacks. Under the control of Cindy, there are two possible decoding methods for participants to obtain each other's information, improving communication security. In addition, this protocol does not involve complex quantum operations and demonstrates a good physical operational feasibility.
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.