Abstract: Disclosed herein is an apparatus and method for synchronizing a block in a blockchain network. The apparatus synchronizes node information of existing participating nodes connected to a blockchain network by joining the blockchain network, determines synchronization target blocks by calculating the current section of a blockchain using an agreed-upon block received from the existing participating nodes, receives a block header of each section and the segment hash table of a snapshot that are verification data for verifying synchronization target data for the synchronization target blocks from participating nodes that are not connected as peers, among the existing participating nodes, generates a snapshot by receiving snapshot segments and the blocks of the current section, which are the synchronization target data, from participating nodes connected as peers, among the existing participating nodes, verifies the snapshot generated from the snapshot segments, and synchronizes the verified snapshot.

Abstract: Disclosed are an apparatus and method for electing a committee node in a blockchain. The apparatus for electing a committee node in a blockchain is configured to transmit a staking transaction including validator information to a blockchain system to register a validator node, generate a draw pool for electing a committee node based on the validator information, change entries of the draw pool using a predefined shuffling algorithm, select a preset number of top entries as votes of a committee member from among the entries of the shuffled draw pool, and elect, as the committee node, the validator node that has acquired votes of a committee.

Abstract: Disclosed herein is a method for adding an additional chain to a blockchain. The method includes depositing, by a node of the blockchain, an asset corresponding to the additional chain; selecting the node as one of consensus nodes for connecting an additional block to the additional chain based on a share value corresponding to the asset; and performing, by the node, distributed consensus for connecting the additional block. Here, nodes constituting the blockchain include major shareholder nodes for processing transactions.

Abstract: Disclosed herein are an apparatus and method for distributed consensus using multi-signature. The apparatus includes one or more processors and executable memory for storing at least one program executed by the one or more processors. The at least one program may send a Pre-Prepare message for processing distributed consensus on a transaction to nodes participating in the distributed consensus in a blockchain network, verify the nodes using message authentication code values included in Prepare messages received from the nodes, send the nodes an A-Prepare message for announcing that the Prepare messages are received from a number of verified nodes equal to or greater than a quorum required for the distributed consensus, generate a multi-signature value using multi-signature fragment values included in Commit messages received from the nodes, and send an A-Commit message including the multi-signature value to the nodes, thereby processing consensus on the transaction.

Abstract: Disclosed is a blockchain system. A blockchain system according to an embodiment of the present disclosure includes: at least one confirmation node; at least one management node configuring a confirmation group by including the at least one confirmation node, and configuring a confirmation block by combining transactions generated in the confirmation group; and an operator node controlling the at least one management node, wherein the at least one management node configures blockchain by combining respective confirmation blocks, wherein the management node configures the blockchain by resetting a parent block on the basis of an generation order of the confirmation blocks and distributes the blockchain.

Abstract: Disclosed is a blockchain system. A blockchain system according to an embodiment of the present disclosure includes: at least one confirmation node; at least one management node configuring a confirmation group by including the at least one confirmation node, and configuring a confirmation block by combining transactions generated in the confirmation group; and an operator node controlling the at least one management node, wherein the at least one management node configures blockchain by combining respective confirmation blocks, wherein the management node configures the blockchain by resetting a parent block on the basis of an generation order of the confirmation blocks and distributes the blockchain.

Abstract: Provided are a method of generating a block chain and an apparatus and method for generating a block. The method of generating a block performed by a node in a block chain network includes receiving a first block from a first node, connecting the received first block to a block chain, determining whether the current node is qualified to generate a second block, which has the first block connected to the block chain as a parent block, generating a second block when the current node is qualified to generate a second block, and transmitting the generated second block to nodes other than the current node. Therefore, it is possible to prevent the waste of energy caused by all nodes performing proof of work for block generation.

Abstract: A method for a node, which is positioned in a network including at least one shard based on regionally divided domains, to process a blockchain transaction in a distributed manner may comprises generating a dynamic committee including a plurality of nodes included in an identical shard; verifying a transaction through the generated committee and generating a transaction block; and storing the generated transaction block in a local ledger to which the node belongs. The at least one shard may include at least one local shard including nodes regionally positioned within a certain range and a global shard including a plurality of nodes belonging to different local shards.

Abstract: Provided is an apparatus for managing zone presence, which manages presence information of a zone including a plurality of wireless access points, including: a presence managing unit receiving a subscription request from an application server and determining whether user terminal access information received from at least any one among the plurality of wireless access points corresponds to the subscription request; and an API processing unit providing the presence information to the application server when the user terminal access information corresponds to the subscription request.

Abstract: An IP multimedia subsystem (IMS)-based service sharing system includes an IMS, a master IMS terminal registered in the IMS, and a slave IMS terminal not registered in the IMS, wherein the master IMS terminal transmits IMS registration information to the slave IMS terminal by using near field communication (NFC), and the slave IMS terminal is registered in the IMS on the basis of the transmitted IMS registration information.

Abstract: A base station and a method of acquiring an IP of a base station by a mobile terminal. According to one exemplary embodiment, a base station includes: an application server to store an application provided to a mobile terminal; a wireless access node to perform wireless communications with the mobile terminal; and a proxy server to manage information of the application server and register an entire domain name of the wireless access node and an IP address thereof to a domain name-IP address conversion server.

Abstract: Provided is an apparatus for managing zone presence, which manages presence information of a zone including a plurality of wireless access points, including: a presence managing unit receiving a subscription request from an application server and determining whether user terminal access information received from at least any one among the plurality of wireless access points corresponds to the subscription request; and an API processing unit providing the presence information to the application server when the user terminal access information corresponds to the subscription request.

Abstract: An IP multimedia subsystem (IMS)-based service sharing system includes an IMS, a master IMS terminal registered in the IMS, and a slave IMS terminal not registered in the IMS, wherein the master IMS terminal transmits IMS registration information to the slave IMS terminal by using near field communication (NFC), and the slave IMS terminal is registered in the IMS on the basis of the transmitted IMS registration information.

Abstract: An individual IMS terminal acquires address and place information of a service discovery server present in the local IP network from an AP. Next, the individual IMS terminal may query the service discovery server to find out an SIP URL address of a sharing IMS terminal. When the individual IMS terminal finds out the sharing IMS terminal, its own IMS subscription information is transmitted to the sharing IMS terminal. The sharing IMS terminal is dynamically registered in the IMS depending on the received IMS subscription information. When the process ends, the sharing IMS terminal has the same IMS subscription information as the individual IMS terminal, such that the session mobility control provided by the IMS may be applied as it is.

Abstract: Disclosed is a file cloud service apparatus that is not a file cloud system for simply sharing a file between users, but a social file cloud server that enables social information about a file shared within a group to be used by including a comment of a user or scores on a file in file metadata information in group sharing. The file cloud service apparatus may construct a single system together with a file cloud client apparatus by adding social information of the user on the file and thereby may provide an efficient social sharing service. The file cloud service apparatus becomes a base for providing a user-oriented file cloud service.