Abstract: The present disclosure relates to a printed circuit board including, a first insulating layer, a first metal layer disposed on the first insulating layer, a bridge disposed on the first metal layer and including a bridge insulating layer and a bridge circuit layer, a second insulating layer disposed on the first insulating layer and covering at least a portion of the bridge, a second metal layer disposed on the second insulating layer, and a connecting via penetrating the bridge and the second insulating layer to connect the first metal layer to the second insulating layer. The connecting via is spaced apart from the bridge circuit layer.

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: Provided are a package structure and a method of forming the same. The method includes providing a first package having a plurality of first dies and a plurality of second dies therein; performing a first sawing process to cut the first package into a plurality of second packages, wherein one of the plurality of second packages comprises three first dies and one second die; and performing a second sawing process to remove the second die of the one of the plurality of second packages, so that a cut second package is formed into a polygonal structure with the number of nodes greater than or equal to 5.

Abstract: An electronic device includes a display device, which may be fabricated using a described method. The display device includes a glass substrate including a first surface, a second surface opposite the first surface, and a side surface between the first surface and the second surface, an outermost structure on the first surface of the glass substrate and located adjacent to an edge of one side of the glass substrate, and a display area including a plurality of light emitting areas on the first surface of the glass substrate and located farther from the edge of the one side of the glass substrate than the outermost structure is. A minimum distance from the side surface of the glass substrate to the outermost structure is equal to 130 ?m or less.

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: A printed circuit board includes: an insulating member; a first wiring layer disposed in the insulating member, and including first and second pattern layers spaced apart from each other based on a thickness direction of the printed circuit board; and a second wiring layer disposed in the insulating member, and spaced apart from the first pattern layer over the first pattern layer based on the thickness direction. Based on the thickness direction, an insulation distance between the first pattern layer and the second pattern layer is smaller than an insulation distance between the first pattern layer and the second wiring layer, and each of the first and second pattern layers is thinner than the second wiring layer.

Abstract: A printed circuit board includes a first board including a plurality of first insulating layers and a plurality of first wiring layers disposed between the plurality of first insulating layers, respectively; and a second board disposed on one surface of the first board and including a plurality of second insulating layers and a plurality of second wiring layers disposed on or between the plurality of second insulating layers, respectively. At least one of the plurality of first insulating layers has a thickness less than a thickness of at least one of the plurality of second insulating layers. The first board further includes a through-via penetrating each of the plurality of first insulating layers and connected to one of the plurality of second wiring layers.

Abstract: A printed circuit board includes: a first insulating layer having a recess portion in one surface of the first insulating layer; a first circuit pattern embedded in the first insulating layer and being in contact with a lower surface of the recess portion; a second insulating layer disposed on the one surface of the first insulating layer to be disposed in at least a portion of the recess portion; and a via penetrating through at least a portion of the second insulating layer, disposed in the recess portion, and connected to the first circuit pattern.

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.