Abstract: According to an embodiment, a communication system includes a plurality of communication apparatuses. Each of the communication apparatuses includes a key generator and a synchronization processor. The key generator generates shared keys shared with another communication apparatus. The synchronization processor synchronizes at least one of order of using the generated shared keys and roles played when the generated shared keys are used, with another communication apparatus based on a rule determined in advance.

Abstract: According to an embodiment, a communication device includes a first manager, and a second manager, a first communication unit, a determination unit, a controller, and a second communication unit. The first manager shares a first cryptographic key with a first external device connected via a link. The second manager shares a second cryptographic key to be provided to an application, with the first external device and with a second external device connected via links. The first communication unit transmits the second cryptographic key to the first external device. The determination unit determines whether a device with which the second cryptographic key is to be shared is the first external device. If it is affirmative, the controller controls the second manager to share, as the second cryptographic key, a cryptographic key obtained by converting the first cryptographic key. The second communication unit provides the application with the second cryptographic key.

Abstract: According to an embodiment, a quantum key distribution device includes a key sharing unit, a correcting unit, a compressor, and a controller. The key sharing unit is configured to generate a shared bit string by using quantum key distribution performed with another quantum key distribution device via a quantum communication channel. The correcting unit is configured to generate a corrected bit string through an error correction process with respect to the shared bit string. The compressor is configured to generate an encryption key through a key compression process with respect to the corrected bit string. The controller is configured to perform a restraining operation in which the total number of bits of encryption keys generated per unit time by the compressor is smaller than the total number of bits of the encryption keys generated per unit time by the compressor in the case of not performing the restraining operation.

Abstract: According to an embodiment, a communication apparatus includes a key storage unit configured to store therein a cryptographic key; a receiving unit configured to receive a message; an analyzing unit configured to analyze whether the message includes an access request for the cryptographic key; a generating unit configured to, when the message includes the access request, generate request information used to request an access to the cryptographic key requested by the access request; and an access controller configured to control the access to the cryptographic key based on the request information.

Abstract: According to an embodiment, a quantum key distribution (QKD) device includes a sharing unit, a correcting unit, a deciding unit, a calculator, and a privacy amplifier. The sharing unit is configured to generate a shared bit string through quantum key distribution with each other QKD device connected via quantum communication channels. The correcting unit is configured to generate a corrected bit string through an error correction process on the shared bit string. The deciding unit is configured to calculate an error rate in the corresponding quantum communication channel with respect to each other QKD device, and decide on a combined error rate from error rates calculated. The calculator is configured to calculate, based on the combined error rate, a length of an encryption key to be shared. The privacy amplifier is configured to generate the encryption key having the calculated length of the encryption key from the corrected bit string.

Abstract: According to an embodiment, a communication device includes a cryptographic communication unit, a first communicating unit, and a control unit. The cryptographic communication unit is configured to perform cryptographic communication with an external device via a first network. The first communicating unit is configured to perform communication with a key generating device via a second network, the key generating device being configured to generate a cryptographic key to be used in the cryptographic communication. The control unit is configured to perform control to transmit an address registration request containing address information to the key generating device via the first communicating unit when a predetermined specific request is issued from among requests used in the cryptographic communication.

Abstract: In general, according to one embodiment, a communication node includes a key synchronization controller and an application communicator. The key synchronization controller controls synchronization of an application key on the basis of a node-based signaling process and a session-based signaling process, where the former process is for starting or ending exchanging of an application key between a correspondent node and the communication node and the latter process is for synchronizing a rule for assignment of the application key to a session with the correspondent node, the session shared with the correspondent node. The application communicator provides the application key in accordance with the rule, the key for use by an application having the session.

Abstract: According to an embodiment, a quantum communication device includes a receiver, a sift processor, an estimator, first and second storages, a determination unit, an error corrector, a measurement unit, and a privacy amplifier. The sift processor acquires sift processing data by referring to a cryptographic key bit string in a predetermined bit string with a reference basis randomly selected from a plurality of bases. The estimator acquires an estimated error rate by estimating an error rate of the sift processing data from an error rate of part of the sift processing data. When a sift processing data volume stored in the first storage is not smaller than a first threshold, the determination unit determines order of the sift processing data to be corrected based on an estimated error rate, an error rate range that a check matrix can correct, and estimated correction time, and the check matrix used for correction.

Abstract: According to an embodiment, a quantum communication device includes a sift processor, an estimator, a determination unit, and a corrector. The sift processor is configured to acquire sift processing data by referring to a cryptographic key bit string in a predetermined bit string with a reference basis randomly selected from a plurality of bases via a quantum communication channel. The estimator is configured to acquire an estimated error rate of the sift processing data. The determination unit is configured to determine order of the sift processing data in which an error is to be corrected based on the estimated error rate and difference data between a processing speed of error correcting processing and a processing speed of privacy amplification processing. The corrector is configured to acquire one piece of the sift processing data in the order determined by the determination unit, and generate error correcting processing data.

Abstract: A transfer unit transfers a message between a network and an external terminal. An input unit inputs a user ID for identifying a user. A generating unit generates a registration message requesting a registration of address information of the user. A transmitting unit transmits the registration message to a server. A receiving unit receives a response message including registration information and connection information from the server. When the connection information indicates a permission of a connection of the external terminal to the network, a control unit controls the transfer unit to transfer the message between the network and the external terminal.

Abstract: According to one embodiment, a transmitter includes a signal dividing unit, a syndrome sending unit, a syndrome receiving unit and a decoding unit. The signal dividing unit divides an original signal into a first signal and a second signal based on a common dividing policy. The syndrome sending unit sends the first syndrome message calculated based on the first signal through a clear channel. The syndrome receiving unit receives a second syndrome message through the clear channel. The decoding unit decodes the second signal by using the second syndrome message to restore a fourth signal, the fourth signal being corresponding to the second signal received by a receiver through a noisy channel.

Abstract: According to an embodiment, a communication apparatus controls controllable nodes. The apparatus includes an acquisition unit and a generation unit. The acquisition unit acquires at least one of a first evaluation value indicating an occurrence frequency of a control request to a target controllable node and a second evaluation value indicating an occurrence frequency of communication error at the target controllable node. The generation unit generates identification information to be assigned to control the target controllable node in a manner such that a bit length of the identification information becomes shorter as at least one of the first evaluation value and the second evaluation value increases.

Abstract: According to an embodiment, a communication apparatus includes a finding unit; a negotiating unit; and a communicating unit. The finding unit is configured to, in response to a request from an application that makes use of key information, find out a key generating device that generates the key information. The negotiating unit is configured to perform a negotiation operation with respect to the key generating device to determine conditions for key information that is to be generated. The communicating unit is configured to receive, from the key generating device, the key information that is generated based on the conditions determined in the negotiation operation, and send the received key information to the application.

Abstract: According to one embodiment, a node is capable of conforming to one of a plurality of Ethernet standards and includes: an Ethernet controller unit that performs auto-negotiation with a switch to exchange information concerning an interface speed, to determine an interface speed to be used based on the information concerning the interface speed, and to receive information including a setting Ethernet standard set as an Ethernet standard to be used; a storage unit that stores a node's available Ethernet standard which is an Ethernet standard to which the node can conform; and a controller that performs setting such that the node operates using a coincident standard between the Ethernet standard stored in the storage unit and setting Ethernet standard and connects a link to the switch.

Abstract: According to an embodiment, an information processing device that includes a first storage unit and a second storage unit having power consumption different from that of the first storage unit. The information processing device also includes a control unit configured to make a control to determine a priority of information that is to be stored in the first storage unit or the second storage unit. The control unit is configured to store the information into the first storage unit or into the second storage unit based on the determined priority.

Abstract: A switching apparatus includes an authentication client unit that requests user authentication to a user authentication server that performs user authentication of the switching apparatus, and, when the requested user authentication is successfully performed, receives from the user authentication server, information of success of the user authentication and setting information used when terminal authentication of a terminal to be connected to the switching apparatus is relayed to a terminal authentication server that performs terminal authentication; an authentication setting unit that sets the setting information to an authentication relay unit that relays terminal authentication; and a control unit that allows the authentication relay unit to relay the terminal authentication when the setting information is set to the authentication relay unit.

Abstract: According to an embodiment, a transmitter transmits first transmission key data and second transmission key data as quantum information. The transmitter includes a first privacy amplifier and a second privacy amplifier. The first privacy amplifier generates first secure key data by performing privacy amplification to remove information that has possibly been acquired by an eavesdropper of the first transmission key data on the first transmission key data. The second privacy amplifier generates second secure key data by performing the privacy amplification to remove information that has possibly been acquired by the eavesdropper of the second reception key data on the decoded key data.

Abstract: According to an embodiment, a communication apparatus includes a cryptographic key storage, a transmitter, a receiver, and a sharing controller. The cryptographic key storage stores therein one or more cryptographic keys shared with an external device. The transmitter transmits specifying information that specifies at least one of the cryptographic keys to the external device. The receiver receives determination information that indicates a result of determination, which is made by the external device based on the specifying information, on whether the shared cryptographic key is consistent between the apparatus and the external device. When receiving the determination information indicating that the shared cryptographic key is inconsistent between the apparatus and the external device, the sharing controller deletes the cryptographic key specified by the specifying information from the cryptographic key storage.

Abstract: According to an embodiment, a communication device includes a storage unit and a determiner. The storage unit is configured to store therein a degree of priority and a first requested volume for each of one or more applications that use an encryption key. The first requested volume indicates a volume of the encryption key requested by the each of applications. The determiner is configured to determine a volume of the encryption key to be assigned to each application in such a way that a first total value that is a total of the volume of the encryption key to be assigned to the application is equal to or smaller than a second total value that is a total value of a volume of the encryption key assignable and that the encryption key of the first requested volume is preferentially assigned to the application whose degree of priority is higher.

Abstract: According to an embodiment, a communication device includes an acquirer and a determiner. The acquirer is configured to acquire a first history value for each of one or more applications that use an encryption key. The first history value indicates a history value of a volume of the encryption key used by the each of one or more applications. The determiner is configured to determine a volume of the encryption key to be assigned to the corresponding application, according to the first history value.