Abstract: A decentralized group signature method for an issuer-anonymized credential system includes (a) an initial system setup operation of defining elements of a group signature method and information that is generated and shared by each group member, (b) an initial group member setup operation, (c) a group member participation operation of adding a new group member to a group, (d) a group signature operation of putting a group signature on a specific message, (e) an operation of verifying the group signature, (f) an operation of removing anonymity from a group signature for a specific group member with agreement of group members, and (g) an operation of revoking a specific group member with agreement of the group members. Exclusive authority of a group manager is distributed to the group members.

Abstract: Provided are an electronic device and method for managing a decentralized identifier (DID) and more specifically a device and method for managing a DID by giving authority over the DID to a user according to a priority level selected by the user.

Abstract: An off-chain data storage method and apparatus for supporting the integrity and capacity scalability of a data object stored in an off-chain storage. The off-chain data storage method includes collecting a plurality of transactions for a plurality of data objects, creating a root transaction on the basis of a Merkle root of a Merkle tree created based on the collected transactions, and storing the root transaction in a blockchain storage.

Abstract: Disclosed is a method of operating a software-defined network (SDN) controller located in a decentralized SDN including a plurality of SDN switches and a plurality of SDN controllers, the method including receiving a transaction including network event information from at least one SDN switch of the plurality of SDN switches, determining a block generation entity with at least one other SDN controller based on a consensus algorithm, and, when the SDN controller is determined as the block generation entity, generating a block including the transaction and propagating the block to the at least one other SDN controller and the plurality of SDN switches. Also, a corresponding method of operating a SDN switch is disclosed.

Abstract: A decentralized group signature method for an issuer-anonymized credential system includes (a) an initial system setup operation of defining elements of a group signature method and information that is generated and shared by each group member, (b) an initial group member setup operation, (c) a group member participation operation of adding a new group member to a group, (d) a group signature operation of putting a group signature on a specific message, (e) an operation of verifying the group signature, (f) an operation of removing anonymity from a group signature for a specific group member with agreement of group members, and (g) an operation of revoking a specific group member with agreement of the group members. Exclusive authority of a group manager is distributed to the group members.

Abstract: Provided are an electronic device and method for managing a decentralized identifier (DID) and more specifically a device and method for managing a DID by giving authority over the DID to a user according to a priority level selected by the user.

Abstract: An off-chain data storage method and apparatus for supporting the integrity and capacity scalability of a data object stored in an off-chain storage. The off-chain data storage method includes collecting a plurality of transactions for a plurality of data objects, creating a root transaction on the basis of a Merkle root of a Merkle tree created based on the collected transactions, and storing the root transaction in a blockchain storage.

Abstract: Disclosed is a method of operating a software-defined network (SDN) controller located in a decentralized SDN including a plurality of SDN switches and a plurality of SDN controllers, the method including receiving a transaction including network event information from at least one SDN switch of the plurality of SDN switches, determining a block generation entity with at least one other SDN controller based on a consensus algorithm, and, when the SDN controller is determined as the block generation entity, generating a block including the transaction and propagating the block to the at least one other SDN controller and the plurality of SDN switches. Also, a corresponding method of operating a SDN switch is disclosed.

Abstract: The present invention relates to a network device that supports software defined networking (SDN) and a packet processing method in the network device. The network device in accordance with the present invention includes: a flow table configured to store a processing action for each flow; and a packet processing module configured to search the flow table for a flow entry matched with a packet being received to determine a list of processing actions for the packet. Here, the packet processing module is configured to use inheritance relationship information between flows defined in the flow table to generate an action list that includes one or more actions for the packet in order to determine the processing actions for the packet.

Abstract: A method for sending and receiving a data through multiple communication paths and an apparatus for receiving a data through multiple communication paths. A method for receiving a data through multiple communication paths by an apparatus for receiving a data includes receiving at least t (here, 0<t=n and n and t are natural numbers) of n shares generated from one unit data by a threshold encryption scheme by an apparatus for sending a data and sent through multiple communication paths on a network; and recovering the unit data using the at least t shares. According to exemplary embodiments of the present invention, data may be sent and received while ensuring confidentiality, integrity, and availability.

Abstract: The present invention provides content providing apparatus and method and a content providing system which maintains a compatibility with an IP network and deliver a content with a complete distributed architecture excluding the content synchronizing process and the request routing process which delivers the content.

Abstract: Extension of a function of an Software defined networking (SDN) network device is provided. The network device includes a plurality of flow tables, a plurality of function modules configured to perform different processing on a packet, and an entry module configured to determine an operation to be performed first on the packet between a table search operation and a function module execution operation, in which as a result of the operation determined by the entry module, a table search operation or a function module execution operation to be performed next is designated, and the designation is repeated until an output instruction for the packet is given.

Abstract: A method for sending and receiving a data through multiple communication paths and an apparatus for receiving a data through multiple communication paths. A method for receiving a data through multiple communication paths by an apparatus for receiving a data includes receiving at least t (here, 0<t=n and n and t are natural numbers) of n shares generated from one unit data by a threshold encryption scheme by an apparatus for sending a data and sent through multiple communication paths on a network; and recovering the unit data using the at least t shares. According to exemplary embodiments of the present invention, data may be sent and received while ensuring confidentiality, integrity, and availability.

Abstract: The present invention relates to a network device that supports software defined networking (SDN) and a packet processing method in the network device. The network device in accordance with the present invention includes: a flow table configured to store a processing action for each flow; and a packet processing module configured to search the flow table for a flow entry matched with a packet being received to determine a list of processing actions for the packet. Here, the packet processing module is configured to use inheritance relationship information between flows defined in the flow table to generate an action list that includes one or more actions for the packet in order to determine the processing actions for the packet.

Abstract: A method of assuring QoS in consideration of fairness in a contention-based wireless network and a terminal for the same are provided. When a token is allocated by a wireless access point, the terminal determines priority of a data frame which the terminal intends to use in communication, through a scheme of splitting the allocated token. Therefore, fairness can be assured by selection of the terminal.

Abstract: Disclosed is a Quality of Service (QoS) providing method and apparatus in a software-defined networking (SDN) based network, the QoS providing method including receiving a first packet of a predetermined flow, searching for forwarding information corresponding to the packet and QoS rule information corresponding to the packet in a forwarding table and a QoS rule table, respectively, transmitting the packet to a controller if the forwarding information and the QoS rule information do not exist in the forwarding table and the QoS rule table, and generating a flow entry corresponding to the packet in a flow learning table based on forwarding information and QoS rule information that are received from the controller, thereby efficiently providing QoS.

Abstract: Provided is a network address translation (NAT) apparatus including: a NAT unit translating an address so as for a client and a server to communicate with each other through an outside network by referring to a NAT table that manages an inside IP address and an outside IP address mapped to the inside IP address; and a cookie proxy unit providing a cookie to the client by referring to a connection cookie table that manages a cookie corresponding to the outside IP address when there is a cookie request from the client.

Abstract: Provided is a method for hiding a server address including: requesting, by a client, communication with a server to a contact point through a first network path; requesting, by the contact point, communication with the client to the server; and communicating, by the server and the client, with each other through a second network path by encrypting a server address.

Abstract: Extension of a function of an Software defined networking (SDN) network device is provided. The network device includes a plurality of flow tables, a plurality of function modules configured to perform different processing on a packet, and an entry module configured to determine an operation to be performed first on the packet between a table search operation and a function module execution operation, in which as a result of the operation determined by the entry module, a table search operation or a function module execution operation to be performed next is designated, and the designation is repeated until an output instruction for the packet is given.

Abstract: A packet scheduling method and apparatus which allows multiple flows that require data transmission to the same output port of a network device such as a router to fairly share bandwidth. The packet scheduling method includes calculating an expected time of arrival of a (k+1)-th packet subsequent to a currently input k-th packet of individual flows by use of bandwidth allocated fairly to each of the flows and a length of the k-th packet; in response to the arrival of the (k+1)-th packet, comparing the expected time of arrival of the (k+1)-th packet to an actual time of arrival of the (k+1)-th packet; and scheduling the (k+1)-th packet of each flow according to the comparison result.