Method for Making Tag in Broadcast Encryption System

The method of forming a tag in a broadcast encryption system is disclosed. The present invention, further comprising: in the tag forming method used in a broadcast encryption system of the hierarchy including a plurality of node groups of nodes the predetermined number, detecting the at least one leaf node, except (a), ( b) setting a node ID assigned to the at least one node belonging to the at least one leaf node, except of which the node ID constituting the 0th hierarchy assigned node to the node path IDs at the 0th layer of the leaf node, and comprising: at least one connection of a node path ID to the sequence in which the node ID increases of leaf nodes corresponding to forming the tag list for the 0th hierarchy, and (c) (b) step by performing repeatedly to the last layer last It is implemented through the forming to the tag list for the layer. In accordance with the present invention, there is an effect that throughput is significantly reduced in the server in the BE system in accordance with a reduction in tag size. Broadcast cryptography, the excluded node, tag table, the tag information, the node path IDs