摘要:
A key update method and a key update apparatus are provided. The method includes storing data in a database of an update server, the data having an encoded updated node key in response to a node key update for a group; selecting necessary data, from among the data having the encoded updated node key, to calculate a key immediately prior to when the member is switched to the online mode, and generating member update data; and performing a key update with respect to the member using the member update data in a device corresponding to the member which has switched from the offline mode to the online mode.
摘要:
A group key update method and a group key update apparatus for updating a key of members in a group are provided. The group key update method includes selecting a sub-root node among nodes on the binary tree; performing a node change with respect to the group according to a type of the sub-root node, and generating a changed binary tree; and performing a node key update with respect to the changed binary tree.
摘要:
A video fingerprint insertion apparatus is provided. A frequency domain selection unit selects a frequency domain into which a fingerprint is inserted, from frequency domains of a video; a fingerprint insertion position determination unit determines a position where the fingerprint is to be inserted, based on a fingerprint insertion determination value in the selected frequency domain; and a fingerprint insertion unit inserts a fingerprint bit stream whose insertion strength is controlled, to the position where the fingerprint is to be inserted.
摘要:
A method and device for updating a group key are disclosed. The group key updating method comprises determining a start node for a key update on a binary tree, updating a node key of the start node for a key update, updating a node key of a parent node of a node corresponding to the updated node key using the updated node key, and repeatedly performing the updating of the node key of the parent node, and then updating a node key corresponding to a root node of the binary tree. With the disclosed method and device, it is possible to efficiently perform a group key update process.
摘要:
A rekey index generation method and a rekey index generation apparatus are provided. The rekey index generation method includes inserting join information to a first field of a rekey index when new members join a group; and inserting node numbers, corresponding to each of the new members, into a second field of the rekey index for a receiver to select a necessary key from among transmitted encoded keys.
摘要:
A method and device for updating a group key are disclosed. The group key updating method comprises determining a start node for a key update on a binary tree, updating a node key of the start node for a key update, updating a node key of a parent node of a node corresponding to the updated node key using the updated node key, and repeatedly performing the updating of the node key of the parent node, and then updating a node key corresponding to a root node of the binary tree. With the disclosed method and device, it is possible to efficiently perform a group key update process.
摘要:
A group key update method and a group key update apparatus for updating a key of members in a group are provided. The group key update method includes selecting a sub-root node among nodes on the binary tree; performing a node change with respect to the group according to a type of the sub-root node, and generating a changed binary tree; and performing a node key update with respect to the changed binary tree.
摘要:
A rekey index generation method and a rekey index generation apparatus are provided. The rekey index generation method includes inserting join information to a first field of a rekey index when new members join a group; and inserting node numbers, corresponding to each of the new members, into a second field of the rekey index for a receiver to select a necessary key from among transmitted encoded keys.
摘要:
Provided are a method of generating a node identifier including padding information and location information, in a tree structure, a computer-readable storage medium storing a program for executing a method of generating a node identifier in a tree structure, and a terminal apparatus using the tree structure. The location information is generated by using branch identifiers, each of the branch identifiers being allocated for each branch from a root node to a target node. The padding information is generated by a padding code, which includes information about a group of the target node, and depth information, which includes information about a level of the target node in the tree structure.
摘要:
A method and apparatus for updating a group key of a group corresponding to a binary tree are provided. The method includes updating keys of leaf nodes that correspond to new members, in response to a join of at least two new members joining the group; determining whether both of two child nodes of a single ancestor node are updated when updating a key of the single ancestor node of the leaf nodes; establishing one of the two child nodes as an update use node when both the two child nodes are updated; and updating a key of the ancestor node using the updating node. Thus, the group key may be effectively updated with respect to multi-join.