METHOD OF UPDATING KEY AND KEY UPDATE DEVICE USING THE SAME

摘要

A key update method and a key update device using the same are provided to perform a member key update process by using only update data in on-line states of devices. An encrypted data storage process is performed to store encrypted data including an updated node key in a database(910) of an update server in response to a node key update request for a group. A member(920) generates member update data by selecting data necessary for producing a key prior to an on-line state from the encrypted data including the updated node key. A device corresponding to the member of the on-line state performs a key update process for the member by using the member update data.