Abstract: A method for issuing non-fungible tokens based on time-context data to be used for supporting transactions of historical time slots includes steps of: (a) an NFT platform server, in response to acquiring a specific intention, determining whether at least one specific issuance condition for at least one specific token corresponding to at least one specific historical time slot is satisfied; and (b) the NFT platform server, in response to determining that the specific issuance condition is satisfied, transmitting a specific transaction indicating that an issuance of the specific token is valid to at least part of nodes included in the blockchain network, to thereby update the nodes in the blockchain network and thus enable the issuance of the specific token corresponding to the specific historical time slot.

Abstract: A method for synchronizations with delayed data serving as backup data stored in one or more delayed nodes in a blockchain network, to thereby restore one or more service nodes in the blockchain network while maintaining a reliability of the backup data is provided. The method includes steps of: (a) a specific delayed node among the delayed nodes performing synchronization with the services nodes while the specific delayed node maintains a specific delay according to a specific initial setting thereof; (b) the specific delayed node, when a triggering command is acquired from an administrating device, transmitting information on delayed blocks included therein to the service nodes in order to support restoration of the service nodes; and (c) the specific delayed node, after the service nodes are restored by using the information on the delayed blocks, performing the synchronization again with the service nodes.

Abstract: A method for providing a blockchain network capable of optimizing storage used by service nodes in the blockchain network is provided. The method includes steps of: (a) a specific service node among the service nodes, wherein the specific service node is configured to optimize its storage if one of optimization conditions is satisfied, generating blocks while synchronizing with other service nodes; and (b) the specific service node (b1) determining whether one of the optimization conditions is satisfied, by referring to one of (i) (i-1) a latest-block number of a latest block among the blocks and (i-2) a predetermined threshold number, and (ii) a predetermined threshold time and (b2) if one of the optimization conditions is satisfied, applying storage-optimizing operation to information on transactions in target blocks which are part of the blocks not optimized, wherein the target blocks are determined by referring to one of (i) and (ii).