49 results about "Bell state" patented technology

The present invention relates to the technical field of communications. Disclosed is a two-party quantum secret magnitude comparison method based on a two-level bell state. The present invention comprises the following steps: step I: protocol participants Alice and Bob respectively possessing their own secret values SA and SB, and Alice and Bob sharing a secure n-bit key KAB=KAB1KAB2KKABn by means of QKD; and step II: Alice and Bob sharing a collision-resistant hash function Hash(.) that is resistant to quantum algorithms, and with the assistance of a semi-trusted third party (TP), Alice and Bob completing the comparison between the magnitudes of the secret values of the two. By means of the present invention, an equality relationship and magnitude relationship between the secret values of the two participants, i.e. Alice and Bob, can be effectively determined; a quantum state prepared by the TP is a two-particle maximally entangled Bell state; and by means of the first eavesdropping detection, the absence of eavesdroppers and the honesty of the TP are verified.

The invention relates to the technical field of quantum information, and discloses a method for controllably and remotely executing any target quantum operation of a single quantum bit, and the method comprises the steps: employing a one-dimensional five-quantum-bit cluster state as an entanglement resource, and forming a quantum information transmission channel through the reasonable configuration of quantum bits; quantum bit measurement and classical information transmission are executed by an information control party, and generation of a channel access authorization key and secure transmission of a target quantum state are realized; the operation executor executes a series of quantum operations and Bell state measurement according to the received classic information and transmits a measurement result to the receiving agent; and the receiving agent executes a dynamic conversion operation according to the received classical information and the channel access authorization key, and finally controlled remote execution of the target quantum operation is realized. According to the method and the device, the confidential quantum information is quickly and safely transmitted under the condition that the operation executor does not completely trust the receiving member.

Methods and systems are provided for performing an encoded n-qubit GHZ measurement on n encoded (logical) qubits using encoded Bell state measurements (E-BSMs). Each E-BSM comprises a plurality of dual-rail Bell state measurements (DR-BSMs) performed on pairs of dual-rail encoded photonic qubits (DR-qubits). Methods and systems for using encoded n-qubit GHZ measurements for fault-tolerant measurement-based quantum computation are also provided.

The invention relates to a quantum key distribution method and device based on a double-field protocol, and a storage medium, and the method comprises the following steps: carrying out the phase and intensity modulation of an initial laser pulse through a quantum state preparation device, and generating a double-field quantum state sequence containing a first quantum state sequence and a second quantum state sequence; the sequences are subjected to polarization state coding and time division multiplexing through a quantum channel transmission device to form a coded quantum state transmission sequence. The sequence is then subjected to phase compensation and noise suppression to obtain an optimized quantum state sequence. And then, the quantum state measurement device executes Bell state measurement and basis vector selection on the optimized sequence to obtain a measurement result sequence. And finally, the post-processing device performs key extraction and privacy amplification on the measurement result to ensure that a final quantum key is generated, so that the technical problem that the practicability and the transmission distance of a traditional quantum key distribution scheme are greatly limited due to the influence of channel loss and noise interference factors is solved.

This paper proposes a single-state multi-party semi-quantum secret sharing method based on d-dimensional Bell states, which achieves the goal of "the sender's key can only be recovered when all receivers work together." This method has been proven to be resistant to both external and participant attacks. The method is applicable to d-dimensional quantum systems, uses only a single d-dimensional Bell state as the initial quantum resource, and requires neither quantum entanglement exchange nor unitary operations.

The application discloses a kind of machine room equipment intelligent remote operation and maintenance method and platform, it is related to intelligent operation and maintenance technical field, including, construct bayesian probability model, and combine optical signal characteristics and current harmonic characteristics, predict the failure probability distribution of machine room equipment;According to the failure probability distribution of machine room equipment, convert fault coordinates into equipment logical identifier, and detect the quantum teleportation link of machine room equipment, generate machine room equipment switching instruction according to detection result;According to machine room equipment switching instruction, send Bell state measurement command to fault equipment, and carry out quantum state reconstruction and machine room equipment switching.The application constructs multilayer bayesian probability model based on Gaussian distribution, Granger causality test and variational inference, realizes the nonlinear correlation analysis of optical signal wavelength shift and current harmonic characteristics, can accurately capture the weak signs of potential equipment failure, to significantly improve the sensitivity and reliability of failure prediction.

The invention relates to quantum key distribution, in particular to a quantum key distribution system and method of a single copy QPA based on hyper-entanglement, a hyper-entanglement photon pair source synchronously generates a hyper-entanglement photon pair which is in a maximum entanglement Bell state at a polarization degree of freedom and an energy-time degree of freedom; the QPA processing module is positioned in the transmitting end Alice and the receiving end Bob, and is used for projecting energy-time high-dimensional entanglement to a path degree of freedom and realizing deterministic CNOT gate operation between different degrees of freedom in a single photon; the detection and post-processing module is located in the transmitting end Alice and the receiving end Bob, selects coincidence events with consistent detection results, and generates a final security key by using a distilled entangled state with higher fidelity on the degree of freedom of polarization; according to the technical scheme provided by the invention, the defect that reliable quantum key distribution is difficult to realize in a complex channel environment in the prior art can be effectively overcome.

The invention relates to a novel quantum secret sharing method based on a Bell state. The method comprises the following steps that: firstly, a secret distributor sends a sequence of mixed Bell states and decoy particles to participants; secondly, the participants encode secret shares of the participants into corresponding Pauli operators, and the Pauli operators are applied to the received particle sequences; and finally, the participants recover the shared secret information through cooperation. And shared secret information can be obtained by executing Bell-based measurement by a secret distributor. Compared with other quantum secret sharing methods, the method has the advantages that the secret distributor does not grasp the secret share of the participant, even if the secret distributor grasp the shared secret information, the secret share of the participant cannot be deduced, and the privacy and benefits of the participant can be effectively protected. On the basis of meeting safety, a Bell state is used as a quantum carrier, and compared with an entangled state of n particles, the Bell state is easier to prepare; and meanwhile, various eavesdropping attacks can be effectively resisted. Compared with a traditional method, the method is more practical and higher in efficiency.

This invention belongs to the field of quantum dialogue and discloses a one-step quantum dialogue method. In this method, communicator A prepares a large number of identical polarization-spatial hyperentangled states and sends one photon from each hyperentangled state to communicator B through a quantum channel, establishing a hyperentangled quantum channel between the two parties. After confirming the security of the photon transmission process, both parties encode the photon pairs according to the information to be transmitted. Then, by running nonlocal Bell state measurements and publishing the detector responses, both parties can read the information transmitted by the other, thus achieving bidirectional quantum communication, i.e., quantum dialogue. Compared with existing quantum dialogue protocols, this invention reduces the number of photon transmissions in the channel from two to one, simplifying experimental operations and effectively reducing the photon loss rate, which can effectively promote the practical application of quantum dialogue.

The invention discloses a controlled semi-quantum dialogue method and system based on semi-quantum cryptography and an entangled Bell state. Wherein a manager Charlie prepares a large number of entangled photon pairs, and splits the photon pair in each entangled state into a coding sequence and a test sequence. Only under the condition that the channel is ensured to be safe, the quantum communication party Alice and the classic communication party Bob can code in the sequence in sequence, and finally the code is returned to the management party Charlie for measurement to complete communication. According to the method, the quantum communication party and the classical communication party can exchange secret information at the same time under the supervision of the management party Charlie, that is, only through the permission of the management party Charlie. In addition, compared with a one-way semi-quantum communication protocol, the communication efficiency is remarkably improved by introducing a dialogue mechanism. Compared with a complex GHZ state, the Bell state adopted by the invention is simpler and more convenient in preparation, so that the implementation difficulty is reduced.

Disclosed is a quantum diagnostic circuit, which includes an input unit having an input of at least first to fourth qubits, a diagnostic circuit unit receiving the first to fourth qubits from the input unit and providing a quantum superposition and a quantum entanglement, and an output unit receiving an output of the diagnostic circuit unit and determining whether the output is in a Bell-state, and the diagnostic circuit unit includes a Hadamard gate processing the first qubit to provide the quantum superposition of the first to fourth qubits, a first CNOT gate providing the quantum entanglement between an output of the Hadamard gate and the second qubit, a second CNOT gate providing the quantum entanglement between an output of the first CNOT gate and the third qubit, and a third CNOT gate providing the quantum entanglement between an output of the second CNOT gate and the fourth qubit.

The invention belongs to the technical field of three-dimensional quantum entangled state preparation, and relates to a three-dimensional quantum entangled state preparation method based on photon-assisted Raman transition, a three-energy-level system is constructed by using photon-assisted Raman transition, a three-dimensional Bell state is directly prepared through single-step operation by using the dynamic symmetry of the three-energy-level system, and by optimizing the quantum circuit design, the three-dimensional quantum entangled state is prepared. A three-dimensional Bell state can be prepared into a three-dimensional GHZ state or a non-local entangled state; the adopted photon-assisted Raman transition technology has the advantages of being short in operation time, high in fidelity and easy to calibrate; by reducing operation steps and optimizing quantum circuit design, error accumulation can be remarkably reduced, evolution time can be shortened, rapid and high-fidelity three-dimensional quantum bit entangled state preparation is achieved, and an efficient and reliable new technical scheme is provided for the field of quantum information processing.

Aspects of the present disclosure relate generally to systems and methods for use in the implementation and / or operation of quantum information processing (QIP) systems, and more particularly, to ion entanglement. Some examples include generating a fused resource-state between atomic qubits of non-neighboring parcels such that the atomic qubit share a Bell state.

This invention discloses a method and system for implementing a completely reference-frame-independent quantum key distribution protocol, belonging to the field of quantum information technology. Alice and Bob, the communicating parties, randomly select mutually unbiased basis vectors to prepare quantum states and send them to a third party, Charlie. Charlie performs Bell state projection measurements and announces the success. Both parties publish the basis vector information, divide the dataset, and calculate the gain and bit error rate. A 3×3 correlation tensor matrix is ​​constructed and singular value decomposition is performed to obtain three reference-frame-independent singular values. The secure key rate is calculated based on the bit error rate. Finally, key negotiation and security enhancement are performed to extract the secure key. This invention does not require basis vector alignment, completely eliminating the dependence on reference frame calibration. It can still stably generate keys even with basis vector drift, and the amount of information required by eavesdroppers is lower, significantly improving the practicality and security of the quantum key distribution system.

The present application provides a method of entanglement swapping in a quantum information network (1) comprising a plurality of nodes including a first and a second endpoint (11a, 11e) and a sequence of intermediary nodes (11b, 11c, 11d) linking the first and the second endpoint. The claimed method comprises repeated entanglement swapping mediated by a BSM-based LOCC between two adjacent elementary links. Upon confirming that all Bell-state measurements are successful, a combined quantum state postprocessing is performed that is conditional on a result of a combined Boolean logic operation. The present application further pertains to a corresponding quantum information network and to an intermediary node for the network.

The invention relates to the technical field of quantum security calculation, and discloses a multi-party multi-data summation method based on a d-dimensional cluster state, which introduces a semi-honest third party to assist in completing summation calculation, and constructs a bidirectional identity authentication process between a participant and the third party by using a dual one-way hash function, thereby effectively preventing identity impersonation attack. In a multi-party multi-data summation stage, a multi-party quantum information interaction structure is established by using quantum entanglement association between a d-dimensional Bell state and a d-dimensional cluster state, and secure coding and aggregation of private data of participants are realized through Bell measurement. Meanwhile, detection particles from (d + 1) groups of complementary bases are randomly inserted into a quantum channel and are used for detecting potential eavesdropping behaviors and ensuring the safety of a quantum communication process.

The invention relates to the technical field of quantum communication, and discloses a method for bidirectionally, controllably, symmetrically and invisibly transmitting two three-quantum-bit target quantum states based on a nine-quantum-bit entangled channel. According to the method, a quantum channel is constructed by using nine-quantum-bit entanglement resources, so that controllable symmetric invisible transmission of two unknown three-quantum-bit exclusive target states is realized, and quantum measurement used in the implementation process only comprises single-quantum-bit measurement and Bell state measurement. The used quantum operation only comprises single quantum bit bubble operation and two quantum bit gate operation, the measurement and operation are realized in a quantum experiment, and the bidirectional controllable quantum teleportation method provided by the invention is large in information capacity, high in transmission efficiency, low in execution difficulty and high in feasibility and practicability.

The present invention discloses a Bell-state-based authenticated multi-party quantum key negotiation method and system, with m-1 participants, P i (i=1,2,...,m‑1), each of which holds its own n-bit secret string #imgabs0# Each participant has an identity information ID of length l i In order to ensure the legitimacy of the participants’ identities, P i (i = 1, 2, …, N-1) require identity authentication with a semi-trusted third party, P0, and each participant shares #imgabs1# with P0. After executing the following steps, these participants will obtain a negotiated key #imgabs3# of approximately #imgabs2# length. As can be seen, Bell states are leveraged to authenticate user identities with the help of a semi-trusted third party, resisting impersonation attacks. Bell states are used as information carriers and transmitted between participants. Encoding operations are designed using quantum state differentiation to ensure the correctness and security of the proposed protocol, which can resist collusion attacks among participants.

According to various embodiments of the present disclosure, provided is a method performed by a first node in a communication system, the method comprising the steps of: transmitting at least one synchronization signal to a second node; transmitting control signals (control information) to the second node; transmitting, to the second node through a quantum channel, a first provision message of a quantum public key (QPK) based on a single qubit or a first particle of a generated bell pair; transmitting, through the quantum channel, a second provision message of the QPK to the second node on the basis of depletion of the QPK stored in a quantum memory of the second node; receiving, from the second node through the quantum channel, a quantum public key encrypted (QPKE) packet in which message information is encoded by the QPK; and obtaining the message information on the basis of quantum state measurement or bell state measurement (BSM) for the QPKE packet.

The application discloses a high-quality quantum network construction method based on self-detection technology and relates to the field of quantum communication, which comprises the following steps: entanglement measurement is performed by using an intermediate node, so that a center node and a plurality of edge nodes share a preset number of pairs of Bell states; the center node and each edge node jointly select half of the Bell states to perform Bell state self-detection, and if the Bell state self-detection is passed, the remaining Bell states are reserved and grouped; half of the groups of shared quantum states are selected to perform generalized GHZ state measurement self-detection, and if the generalized GHZ state measurement self-detection is passed, the center node performs generalized GHZ state measurement on the remaining groups, so that the plurality of edge nodes share high-quality generalized GHZ states. The two-stage device-independent self-detection mechanism is used to screen quantum resources and measurement operations, the quality instability problem caused by noise and loss accumulation in the traditional method is overcome, and it is ensured that the final distributed entangled states have very high fidelity, thereby providing reliable guarantee for subsequent quantum tasks.

The present invention belongs to the field of quantum communication technology and discloses a measurement device-independent quantum dialogue method based on entanglement exchange, in which user B first loads the information to be transmitted into an entangled photon pair through phase encoding. Users A and B establish a long-distance entangled channel through two Bell state measurements at one end of the detection party. User A then performs phase encoding to load the information to be transmitted into its own photon. Both parties then send the photons in their hands to the detection party for a third Bell state measurement. Based on the results of the three Bell state measurements and their respective operations, the two parties can decode the information transmitted by the other party and complete the dialogue. The present invention can effectively resist all attacks from the measurement end and ensure the security of quantum dialogue under the actual conditions of imperfect detection equipment. The present invention uses all linear optical devices, which can be implemented under current experimental conditions and can effectively promote the practical application of MDI-QD.

The invention discloses a non-interactive multi-party dynamic quantum homomorphic encryption method and a non-interactive multi-party dynamic quantum homomorphic encryption device, which can simultaneously ensure that a dynamic processing server is unstable and the problem of errors during T gate homomorphic evaluation is solved in a non-interactive manner, and can be expanded into a multi-client multi-server mode. The method comprises the following steps: (1) generating a Bell state and carrying out secret segmentation; (2) generating an encryption key set; (3) encrypting the corresponding particle set by using the encryption key; (4) evaluating; and (5) decrypting the ciphertext by using the decryption key.

The invention discloses a Bell state and rotation operation-based practical quantum privacy comparison protocol method, which comprises the following steps that: a semi-honest third party prepares S and records the state of the S, and first particles and second particles in all Bell states are respectively utilized to form S1 and S2; first eavesdropping detection is carried out, if the first eavesdropping detection passes, the first participant and the second participant respectively obtain S1 and S2, and the next step is continued, otherwise, communication is stopped; the first participant and the second participant act rotation operations Ry (piX) and Ry (piY) on the S1 and the S2 respectively to obtain SA and SB and send the SA and the SB to the semi-honest third party; the semi-honest third party sequentially executes Bell-based measurement on the SA and the SB to obtain a measurement result, if the measurement result is consistent with the quantum sequence S, the semi-honest third party declares that the privacy information of the first participant and the privacy information of the second participant are the same, otherwise, the privacy information of the first participant and the privacy information of the second participant are different. According to the method, possible information leakage is effectively prevented, the capability of resisting external and internal attacks of the method provided by the invention is remarkably enhanced, and the technical threshold and the cost of implementation are greatly reduced.

The present invention discloses a multi-party semi-quantum secret size comparison method based on two-dimensional Bell state, comprising: 1) participants encrypt their respective secret information; 2) a semi-honest quantum third party (STP) prepares a two-dimensional Bell state and sends a particle sequence A n To Participant P n , where n = {1, 2, ... N}; 3) according to the encrypted information #imgabs0#P n Select the appropriate operation for particle #imgabs1#; 4) After passing the security check, the STP records #imgabs2# and calculates #imgabs3#; 5) Compare the sizes of #imgabs4# and #imgabs5#, and then determine the size relationship of each participant's secret. This is a new method for comparing secret sizes. This method, based solely on two-dimensional Bell states, can perform secret size comparisons. Compared to traditional QPCS and SQPCS methods, this method is much easier to implement with existing quantum technology. Furthermore, based on semi-quantum theory, which reduces quantum costs, this method can compare the secrets of multiple participants simultaneously, making it more applicable and universal.

An apparatus for providing Bell fusion comprises a measurement unit configured to apply a Bell fusion operator to a plurality of Bell blocks 10-1, 10-n corresponding to pairs of photons 1-m in a quantum entanglement state to sequentially measure a zeroth level 10 of a Bell state for each of the plurality of Bell blocks; a selection unit configured to select a Bell fusion operator to be applied to a next Bell block of the plurality of Bell blocks based on a result of measuring a zeroth level of Bell state for a previous Bell block corresponding to the next Bell block; and an identification unit configured to identify a first level of Bell state for a Bell box 20 including the plurality of Bell blocks based on a result of measuring a zeroth level of Bell state for each of the plurality of Bell blocks. A second level for a Bell network is also identified. Bell fusion is achieved using linear optics. Quantum error correction is achieved through a hierarchical Bell state measurement in a feed-forward method increasing the success probability of fusion. Limiting the number of failure for the Bell state measurement improves the limitation of photon losses.

This invention discloses a highly practically secure continuous-variable quantum secret sharing method, belonging to the field of quantum communication technology. Specifically, the method involves: First, establishing a communication scenario consisting of an untrusted measuring party, a distributor, and n participants; the n participants and the distributor prepare their respective quantum states and transmit them to the measuring party through a quantum channel; the measuring party performs Bell state measurements on the quantum states from the participants and the distributor and publishes the measurement results; then, the distributor and participants each randomly select a portion of the quantum state data and, combined with the publicly published measurement results from the measuring party, calculate the transmittance of all channels. Next, the distributor performs classical post-processing with each participant sequentially to obtain their respective keys; finally, the participants and the distributor verify the keys using a hash function. This invention, by having an untrusted third party perform quantum state measurements and publish the results, avoids security vulnerabilities caused by detector non-ideals.

The invention discloses an intelligent remote operation and maintenance method and platform for machine room equipment, and relates to the technical field of intelligent operation and maintenance, and the method comprises the steps: constructing a Bayesian probability model, and predicting the fault probability distribution of the machine room equipment in combination with optical signal features and current harmonic features; according to the fault probability distribution of the machine room equipment, converting the fault coordinate into an equipment logic identifier, detecting a quantum invisible state transmission link of the machine room equipment, and generating a machine room equipment switching instruction according to a detection result; and sending a Bell state measurement command to the fault equipment according to the machine room equipment switching instruction, and performing quantum state reconstruction and machine room equipment switching. According to the method, the multi-layer Bayesian probability model based on Gaussian distribution, Granger causal test and variational inference is constructed, nonlinear correlation analysis of optical signal wavelength shift and current harmonic characteristics is achieved, weak symptoms of potential faults of equipment can be accurately captured, and therefore the sensitivity and reliability of fault prediction are remarkably improved.

This invention discloses a controllable authentication quantum dialogue method based on Bell states, where a third-party quantum dialogue controller C, quantum communicator A, and quantum communicator B share identity authentication information pairwise. The third-party quantum dialogue controller C prepares a Bell state sequence and two Bell state sequences for identity verification. Then, it splits the Bell state sequence into single-particle sequences, sending a portion of the particle sequence to quantum communicator A and quantum communicator B respectively. The third-party quantum dialogue controller C verifies the identity information of quantum communicator A and quantum communicator B, and quantum communicator A and quantum communicator B verify each other's identity information. Quantum communicator A and quantum communicator B each perform unitary operations on the communication particles with the message to be sent. Based on the measurement results of the Bell states after the Bell unitary operations, quantum communicator A and quantum communicator B deduce the message sent by the other party. This method achieves bidirectional secure and efficient communication between quantum communicator A and quantum communicator B under the control of a semi-trusted third-party quantum dialogue controller C, while simultaneously solving the three-party identity authentication problem. The method of this invention is simple and easy to implement, with good practical feasibility.

This invention discloses a controlled semi-quantum dialogue method and system based on Grover's quantum search algorithm. Two classical users entrust a manager, Charlie, to perform quantum searches, thereby achieving bidirectional secure communication. First, Bell states are used to enable the classical user to obtain a shared string, which is then used to encrypt the identifier string. Subsequently, Charlie, based on the search request command, applies Grover's algorithm to sequentially execute the phase flip operator and the diffusion operator, iterating this process times. Finally, Z-basis measurements are used to obtain the target information. This allows classical users to entrust the quantum search algorithm, which they cannot execute independently, to Charlie. Furthermore, the two classical users can only exchange secret information with Charlie's authorization. By introducing Grover's quantum search algorithm mechanism, a quadratic speedup in computational efficiency is achieved.

The present invention provides a method for sharing maximum entangled states in an amplitude-damped channel based on coherence compensation, which relates to the field of quantum communication. Specifically, the distributor Alice prepares a maximum entangled Bell state based on single-particle A and single-particle T, and sends single-particle T to the receiver Bob via an amplitude-damped channel; the receiver Bob performs a quantum controlled NOT gate operation on the prepared single-particle B and the received single-particle T, and then sends single-particle T to the distributor Alice via an amplitude-damped channel; the distributor Alice performs a joint unitary operation on single-particle A and single-particle T, and then performs a single-particle Z-basis measurement on single-particle T, thereby achieving maximum entangled Bell state sharing between two parties in the amplitude-damped channel. This method is also applicable to maximum entangled GHZ state sharing between multiple parties in an amplitude-damped channel. The present invention adopts a coherence compensation mechanism to effectively suppress amplitude damping noise, thereby improving the fidelity of quantum teleportation and multi-party quantum state sharing.