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 multi-user quantum key distribution. The method for multi-user quantum key distribution is performed using a multi-user quantum key distribution apparatus and a quantum key client device, and includes generating, by the multi-user quantum key distribution apparatus, transmission qubit pairs based on a key bit string of a shared key to be distributed to the quantum key client device, measuring, by the quantum key client device, the transmission qubit pairs, received from the multi-user quantum key distribution apparatus through a quantum channel, based on a measurement basis, verifying security of the quantum channel using the transmission qubit pairs, and if the security has been verified, decoding qubit measurement values of the transmission qubit pairs into the shared key.

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.

Abstract: An apparatus and method for providing a Feistel-based variable length block cipher, which are configured to, when plaintext having a certain bit length is encrypted, generate ciphertext having the same bit length as plaintext, and to decrypt ciphertext into plaintext having the same bit length. The apparatus includes an encryption/decryption key generation unit for generating a number of encryption/decryption keys corresponding to a preset number of rounds, based on a secret key, the length of the secret key, the length of plaintext, and a round constant; an encryption/decryption tweak generation unit for generating an encryption/decryption tweak based on a tweak, a length of tweak, and the length of plaintext; and a ciphertext output unit for outputting ciphertext having length identical to that of plaintext, based on plaintext, the length of the plaintext, the length of the secret key, the encryption/decryption keys, and the encryption/decryption tweak.

Abstract: A display device includes a display panel; a middle cabinet including a first support surrounding sides of the display panel and a second support extending inward from inner surfaces of the first support with the display panel seated on the second support; and a sealing-bonding member disposed on the second support abutting the first support to couple the display panel with the middle cabinet and to seal the display panel and the middle cabinet together.

Abstract: An apparatus and method for multi-user quantum key distribution. The method for multi-user quantum key distribution is performed using a multi-user quantum key distribution apparatus and a quantum key client device, and includes generating, by the multi-user quantum key distribution apparatus, transmission qubit pairs based on a key bit string of a shared key to be distributed to the quantum key client device, measuring, by the quantum key client device, the transmission qubit pairs, received from the multi-user quantum key distribution apparatus through a quantum channel, based on a measurement basis, verifying security of the quantum channel using the transmission qubit pairs, and if the security has been verified, decoding qubit measurement values of the transmission qubit pairs into the shared key.

Abstract: An operation apparatus includes a message expansion unit, a state data initiation unit, a state data generation unit, and a chain variable update unit. The message expansion unit generates a plurality of expanded messages using a message. The state data initiation unit generates the initial value of state data using chain variable data. The state data generation unit generates the final value of the state data by iterating a combination function and a step function using the state data and the plurality of expanded messages. The chain variable update unit updates the chain variable data using the state data of the final value.