14 results about "Quantum secure direct communication" patented technology

The present application relates to a quantum key distribution (QKD) and quantum secure direct communication method. The method is applied to a sender, and comprises: processing plaintext information to be sent, so as to obtain a codeword; encrypting the codeword by means of an encryption key in a key pool, so as to obtain ciphertext; performing encoding processing involving increasing the channel capacity by means of masking on the ciphertext, so as to obtain a codeword which has been subjected to encoding involving increasing the channel capacity by means of masking; using a QKD protocol to process the codeword which has been subjected to encoding involving increasing the channel capacity by means of masking, so as to obtain processing result information, wherein the processing result information enables a receiver to acquire a measurement result on the basis of the QKD protocol; on the basis of the QKD protocol, performing QKD post-processing to acquire a QKD post-processing result; and on the basis of the QKD post-processing result, generating a new key, and storing the new key in the key pool. The present solution can not only complete QKD, but also directly transmit a secret message on a quantum channel, and significantly increases the communication distance and communication speed of quantum secure direct communication.

The purpose of the present disclosure is to perform quantum secure direct communication by using a time bin and a phase in a communication system, and a method thereof may comprise the steps of: acquiring system information; performing a random access procedure on the basis of the system information; generating a first signal; transmitting the first signal to a second device; receiving, from the second device, a second signal on which encoding has been performed by using the first signal; and decoding the second signal.

The present specification provides a quantum secure direct communication (QSDC) method by which a transmitting end transmits a message on the basis of differential time coding, in a quantum communication system. More specifically, the method comprises the steps of: receiving, from a receiving end on a quantum channel, (i) at least one initial time state configured by including a time interval equal to a dead time of a single photon detector of the receiving end and (ii) at least one initial phase state; receiving, from the receiving end on a classical channel, time state location information for selecting a specific initial time state for encoding of information transmitted to the receiving end; selecting the specific initial time state for the encoding, on the basis of the time state location information: generating an encoding time state by encoding the information on the basis of the selected specific initial time state, the encoding time state being generated by applying a time shift on the basis of a value of the information being encoded; and transmitting a message including the encoding time state to the receiving end through the quantum channel, wherein the message is restored on the basis of a time difference between information on the at least one initial time state stored in the receiving end and information on the encoding time state.

The present application belongs to the technical field of quantum communication, and discloses a device-independent quantum secret sharing method based on multi-photon entanglement, which requires a key sender to prepare a large number of identical three-photon GHZ states, and to send two photons in each GHZ state to two key receivers respectively; after receiving the photons, the three parties randomly select measurement bases to measure the adversary's photons, and publish the measurement bases and part of the measurement results, so as to estimate the values of Svetlichny polynomials and CHSH polynomials; the security of the transmitted key is ensured by Svetlichny inequality violation and CHSH inequality violation. The present application can resist all attacks from imperfect device ends, reduce the requirement for the security of experimental equipment, effectively enhance the security of QSS under actual experimental conditions, and has important application in the field of future quantum secure direct communication.

The application discloses a quantum secure direct communication method based on passive coding. An information receiver uses two phase random coherent pulses to generate weak coherent pulses in different quantum states through CPBS beam combination and BS attenuation. The information receiver inputs the state of one port output of the BS into a PBS, measures the light intensity ratio of two output ports of the PBS, obtains the state information of the pulse output from the other port of the BS, and sends the state to be sent to an information sender according to the information. The information sender sends the photon pulse back to the information receiver after coding. The information receiver decodes the information sent by the information sender according to the initial pulse information sent by the information receiver. The method does not need to actively modulate the initial quantum state of the light source, realizes passive coding, simplifies the experimental operation, resists side channel attacks of a third-party eavesdropper on the light source modulator, and enhances the communication security.

The application discloses a three-party quantum secure direct communication method with identity authentication function, which realizes three-party quantum secure direct communication with identity authentication function by using polarization-space hyper-encoding single photons; first, Alice prepares polarization-space hyper-encoding single photons and sends the single photons to Bob'1, and the identity of Bob'1 is determined through identity authentication; after the identity of Bob'1 is determined, Bob'1 encodes the single photons in the polarization degree of freedom; then the photon sequence is sent to Bob'2, and the identity of Bob'2 is determined through identity authentication; after the identity of Bob'2 is determined, Bob'2 encodes the single photons in the space degree of freedom; after the encoding is completed, the encoded single photons are re-sent to the information receiver; Alice can obtain the secret information transmitted by the two information senders at the same time through measurement; compared with the previous three-party quantum secure direct communication scheme, the present scheme determines the identities of the two information senders before realizing information transmission, and can effectively improve the security of communication in the actual experimental environment, and has important application in the field of quantum communication.

The application discloses a kind of measurement equipment independent quantum secure direct communication methods based on quantum walk, including encoding in position space in position state and in hardware space in coin state;It is obtained based on quantum walk on straight line that shared entangled state is used as quantum channel;The shared quantum channel is re-described and measured;Quantum channel is detected and the security of quantum channel is judged;Sender and receiver measure and entangle through third party;Sender and receiver confirm the security of quantum channel again;The particle of sender and receiver is merged to obtain composite quantum state;Second quantum walk is carried out to obtain the quantum entangled state of sender and receiver;Sender carries out projection measurement on quantum entangled state and sends the measurement result to receiver, and completes the final measurement equipment independent quantum secure direct communication.The application can realize measurement equipment independent quantum secure direct communication, and reliability is high, and security is good.

The application provides a method for continuous variable quantum secure direct communication, and belongs to the technical field of quantum secure direct communication, and comprises the following steps: a sending end prepares a double-mode compressed entangled light beam pair S, and sends a light beam S1 to a receiving end; the sending end modulates the light beam S1 into a first Laguerre-Gaussian light beam S'1 and sends the light beam S'1 to the receiving end; the sending end selects a subset, measures the orthogonal position and the orthogonal momentum of a light beam S2 in the subset, and compares the measurement result of the light beam S1 with the receiving end to check interference; the receiving end modulates the S'1 into a second Laguerre-Gaussian light beam S''1 according to secret information, and sends the S''1 to the sending end; the sending end recombines the S2 and the S''1 into a light beam pair S' and images, and obtains the secret information according to the imaging result. The application solves the problems that the continuous variable quantum secure direct communication is prone to noise and loss in the transmission process, and the implementation and management are complex.

A controlled quantum secure direct communication method based on multiple groups of Bell bases comprises the following steps: a third party prepares a series of entangled photon pairs to form two photon sequences, and the two photon sequences are respectively sent to two communication parties; and the two communication parties select photons on the photon sequence for two rounds of safety detection. And the third party publishes a preparation base of the entangled photon pair, and an information receiver performs Bell state measurement and records a result according to the preparation base. An information sender publishes random coding positions and coding information, a third party publishes initial states on the positions, a receiver performs second round of security detection, and it is indicated that the channel is free of eavesdropping when the bit error rate is lower than a threshold value. And finally, the third party publishes the initial states of other positions, and the receiver deduces the information to be transmitted by the sender according to the Bell state measurement result. According to the method, only the Bell state needs to be used for communication, and only two rounds of transmission and two rounds of security detection are needed, so that the implementation complexity of a protocol can be reduced, and the communication efficiency is improved.

The objective of the present disclosure is to perform asynchronous measurement device independent quantum secure direct communication (AMDI QSDC) by using an intermediate node in a communication system. The present disclosure may comprise the steps of: acquiring system information; performing an initial access procedure on the basis of the system information; transmitting a first signal for measurement to a second device; receiving information related to a measurement result from the second device; generating, on the basis of the information related to the measurement result, data signals on which data encoding has been performed; and transmitting the data signals to the second device.

The application discloses a quantum secure direct communication method based on a symmetric passive light source, wherein information receivers use four phase random coherent pulses to generate weak coherent pulse beams with random intensity and quantum state through beam splitters and polarization beam splitters interference, beam combination and attenuation, and send the beams to information senders. The information senders send the photon pulses back to the information receivers after encoding. The information receivers decode the information sent by the information senders according to the initial pulse information sent by the information receivers. The method does not need to actively modulate the intensity and quantum state of the light source, can simultaneously realize passive decoy states and passive encoding, can simplify experimental operation, can resist side channel attacks of a light source modulator by a third-party eavesdropper, and can enhance the security of quantum secure direct communication.

The application discloses a quantum secure direct communication method based on quantum walk, which comprises the following steps: encoding an initial state of a quantum walk system; performing one-step quantum walk based on a directed ring graph to obtain a shared entangled state; re-describing a quantum channel shared by a sender and a receiver; the sender performs measurement based on a position-based measurement basis and sends the measurement result to the receiver; the receiver performs corresponding measurement based on a coin-based measurement basis; the sender and the receiver compare measurement results to realize channel judgment; a composite quantum state is calculated; the second-step quantum walk based on the directed ring graph is performed to obtain a final quantum entangled state; the sender performs projection measurement and transmits the receiver; the receiver performs measurement and acquires secret information, thereby completing the quantum secure direct communication based on the quantum walk. The application avoids the advance preparation of the entangled state, avoids the security risk in particle distribution, has higher measurement efficiency and is easier to realize in experiments, and is high in reliability, security and efficiency.

According to various embodiments of the present disclosure, an operation method of a first node in a communication system is provided, the method comprising the steps of: transmitting at least one synchronization signal to a second node; transmitting a control signal to the second node; transmitting, to the second node, a first quantum key packet including a first private key of the first node and a first quantum key based on a key pre-shared between the first node and the second node; receiving, from the second node, a second quantum key packet including a second private key of the second node and a second quantum key based on the pre-shared key; acquiring a first quantum master key based on a first operation and a second operation on the second quantum key, the first operation being on the basis of the first private key and the second operation being related to compensation of the pre-shared key; transmitting, to the second node, a first quantum authenticated secure message in which first message information is encoded on the basis of the first quantum master key; and receiving, from the second node, first feedback related to a first error of the first message information.

A communication method for quantum direct communication and quantum direct communication system, an electronic device and a non-transitory computer-readable storage medium. The quantum direct communication method is applied to a sender of the quantum secure direct communication system. The communication method includes: encrypting a transmitted message by using an encryption algorithm to obtain a ciphertext corresponding to the transmitted message; encoding the ciphertext into a quantum state through a quantum direct communication terminal of the sender according to a quantum communication protocol; and sending the quantum state to a receiver of the quantum direct communication system. According to some embodiments, by utilizing the encryption algorithm to encrypt the transmitted message, the capability of eavesdropper detection is provided for ciphertext transmission, reducing the risk of messages being intercepted by eavesdroppers. Meanwhile, the security of quantum direct communication systems constructed with non-ideal devices is strengthened.