Abstract: Disclosed herein are an apparatus and method for mutual authentication of quantum entities based on Measurement-Device-Independent Quantum Key Distribution (MDI-QKD). The method may include configuring a quantum input form based on an authentication key shared in advance with a counterpart entity, applying polarization modulation to the configured quantum input form, transmitting the quantum input form to which polarization modulation is applied to a quantum measurement device, and authenticating the counterpart entity by checking whether the counterpart entity configures a quantum input form according to the shared authentication key using a measurement result and information about polarization modulation.

Abstract: A quantum entity authentication apparatus and method. The quantum entity authentication apparatus includes a quantum state preparation unit for preparing an authentication quantum state that is generated based on an authentication key previously shared with an entity, a quantum channel verification unit for transmitting a quantum state, generated by performing an operation using a prestored unique operator on the authentication quantum state, to a quantum measurement device, and for verifying security of a quantum channel by using a result of Bell measurement and the authentication quantum state, the result of Bell measurement being revealed by the quantum measurement device for the quantum state, and a quantum entity authentication unit for, when the security of the quantum channel is verified, authenticating the entity using the result of the Bell measurement and the unique operator.

Abstract: An apparatus and method for quantum direct communication using single qubits. The apparatus includes a quantum state preparation unit for preparing quantum states including a message state prepared using pairs of single qubits based on a bit of a message to be sent to a communication partner, an authentication state prepared using random qubit pairs, and a verification state prepared using random qubit pairs, a quantum state communication unit for transmitting the quantum states to the communication partner and measuring a quantum state of a message received from the communication partner, an authentication unit for authenticating, using the authentication state, the communication partner depending on whether an authentication key previously shared with the communication partner is possessed, a verification unit for verifying security of a quantum channel using the verification state, and a message restoration unit for restoring the received message using the message state.

Abstract: A quantum key distribution (QKD) node apparatus and a QKD method therein. The QKD node apparatus may include a QKD module for generating quantum keys and quantum key IDs, a quantum key synchronization management module for storing the quantum keys and the quantum key IDs as outbound and inbound quantum keys in a distributed manner and sharing the outbound and inbound quantum keys with a second QKD node apparatus, and a quantum key orchestration module for delivering a master key and a master key ID to a secure application connected therewith in response to a request for the master key with the ID of a second secure application and delivering a packet including the master key encrypted with the outbound quantum key shared with the second QKD node apparatus, the master key ID, and a quantum key ID, to the second QKD node apparatus.

Abstract: A quantum key distribution (QKD) node apparatus and a QKD method therein. The QKD node apparatus may include a QKD module for generating quantum keys and quantum key IDs, a quantum key synchronization management module for storing the quantum keys and the quantum key IDs as outbound and inbound quantum keys in a distributed manner and sharing the outbound and inbound quantum keys with a second QKD node apparatus, and a quantum key orchestration module for delivering a master key and a master key ID to a secure application connected therewith in response to a request for the master key with the ID of a second secure application and delivering a packet including the master key encrypted with the outbound quantum key shared with the second QKD node apparatus, the master key ID, and a quantum key ID, to the second QKD node apparatus.

Abstract: A single-photon detection method and apparatus. The single-photon detection method detects a single photon using a single-photon detection apparatus, and includes generating an output signal through a photon detector by receiving a light signal as an input, generating a negative voltage comparison result through a negative voltage comparator by receiving the output signal as an input, and generating a photon detection result based on the negative voltage comparison result.

Abstract: A single-photon detection method and apparatus. The single-photon detection method detects a single photon using a single-photon detection apparatus, and includes generating an output signal through a photon detector by receiving a light signal as an input, generating a negative voltage comparison result through a negative voltage comparator by receiving the output signal as an input, and generating a photon detection result based on the negative voltage comparison result.

Abstract: A quantum entity authentication apparatus and method. The quantum entity authentication apparatus includes a quantum state preparation unit for preparing an authentication quantum state that is generated based on an authentication key previously shared with an entity, a quantum channel verification unit for transmitting a quantum state, generated by performing an operation using a prestored unique operator on the authentication quantum state, to a quantum measurement device, and for verifying security of a quantum channel by using a result of Bell measurement and the authentication quantum state, the result of Bell measurement being revealed by the quantum measurement device for the quantum state, and a quantum entity authentication unit for, when the security of the quantum channel is verified, authenticating the entity using the result of the Bell measurement and the unique operator.

Abstract: An apparatus and method for a reliable quantum signature. The method using the apparatus for a reliable quantum signature includes preparing a quantum signature by sharing a first secret key and a first Bell state with a signer's terminal device and by sharing a second secret key and a second Bell state with a verifier's terminal device; signing, by the signer's terminal device, a message with the quantum signature using a first encoding value, the first secret key, and the first Bell state; verifying, by the apparatus, the quantum signature of the message using the first encoding value, the first secret key, and the first Bell state; and finally verifying, by the apparatus, the quantum signature of the message using the verifier's terminal device, a second encoding value, a third encoding value, the second secret key, and the second Bell state.

Abstract: An authentication apparatus and method for quantum cryptography communication. The quantum cryptography communication authentication method is performed using quantum cryptography communication authentication apparatuses, and includes transmitting, by a first quantum cryptography communication authentication apparatus, a quantum state to a second quantum cryptography communication authentication apparatus by selecting a first basis, and measuring, by the second quantum cryptography communication authentication apparatus, the quantum state by selecting a second basis, and performing, by the first quantum cryptography communication authentication apparatus and the second quantum cryptography communication authentication apparatus, authentication by revealing the first basis and the second basis and by comparing sifted keys generated from a common basis between the first basis and the second basis with each other.

Abstract: A quantum communication control apparatus, a quantum communication system having the quantum communication control apparatus, and a method for designing the quantum communication control apparatus. The quantum communication control apparatus includes a first control board configured to include a plurality of connectors and to reconstruct respective functions or signal standards of the plurality of connectors, and at least one second control board configured to include a connector to be connected to any one of the plurality of connectors and to control an optical system implemented according to a protocol or a modulation scheme of quantum communication.

Abstract: An apparatus and method for quantum direct communication using single qubits. The apparatus includes a quantum state preparation unit for preparing quantum states including a message state prepared using pairs of single qubits based on a bit of a message to be sent to a communication partner, an authentication state prepared using random qubit pairs, and a verification state prepared using random qubit pairs, a quantum state communication unit for transmitting the quantum states to the communication partner and measuring a quantum state of a message received from the communication partner, an authentication unit for authenticating, using the authentication state, the communication partner depending on whether an authentication key previously shared with the communication partner is possessed, a verification unit for verifying security of a quantum channel using the verification state, and a message restoration unit for restoring the received message using the message state.

Abstract: A quantum direct communication with user authentication and an apparatus using the same. The quantum direct communication method includes performing verification of security of a quantum channel using a preset channel verification probability and a quantum state source generated by a receiver of quantum direct communication, performing user authentication using one or more of a preset user authentication probability, the quantum state source, and an authentication key shared between the receiver and a sender, stopping quantum direct communication and resetting the quantum channel when the verification of security of the quantum channel fails, and stopping quantum direct communication when the user authentication fails.

Abstract: An apparatus and method for a reliable quantum signature. The method using the apparatus for a reliable quantum signature includes preparing a quantum signature by sharing a first secret key and a first Bell state with a signer's terminal device and by sharing a second secret key and a second Bell state with a verifier's terminal device; signing, by the signer's terminal device, a message with the quantum signature using a first encoding value, the first secret key, and the first Bell state; verifying, by the apparatus, the quantum signature of the message using the first encoding value, the first secret key, and the first Bell state; and finally verifying, by the apparatus, the quantum signature of the message using the verifier's terminal device, a second encoding value, a third encoding value, the second secret key, and the second Bell state.

Abstract: An authentication apparatus and method for quantum cryptography communication. The quantum cryptography communication authentication method is performed using quantum cryptography communication authentication apparatuses, and includes transmitting, by a first quantum cryptography communication authentication apparatus, a quantum state to a second quantum cryptography communication authentication apparatus by selecting a first basis, and measuring, by the second quantum cryptography communication authentication apparatus, the quantum state by selecting a second basis, and performing, by the first quantum cryptography communication authentication apparatus and the second quantum cryptography communication authentication apparatus, authentication by revealing the first basis and the second basis and by comparing sifted keys generated from a common basis between the first basis and the second basis with each other.

Abstract: A quantum direct communication with user authentication and an apparatus using the same. The quantum direct communication method includes performing verification of security of a quantum channel using a preset channel verification probability and a quantum state source generated by a receiver of quantum direct communication, performing user authentication using one or more of a preset user authentication probability, the quantum state source, and an authentication key shared between the receiver and a sender, stopping quantum direct communication and resetting the quantum channel when the verification of security of the quantum channel fails, and stopping quantum direct communication when the user authentication fails.