Node distributed with group key and group key updating

摘要

According to one embodiment, a node that is a root node of a network forming a directed acyclic graph topology, which is composed of plural nodes including the node serving as the root node and having a parent-child relationship among nodes of adjacent hierarchies, includes a generating unit, an encrypting unit, and a transmitting unit. The generating unit generates a group key, and a list indicating a first node to which a distribution of the group key is inhibited. The encrypting unit encrypts the group key so as to be capable of being decrypted by a first child node other than the first node out of the child nodes of the root node. The transmitting unit transmits a first message, including an encrypted group key, which is the group key that is encrypted with respect to the first child node, and the list.

主权项

1. A node that is a root node of a network forming a directed acyclic graph topology by plural nodes, the plural nodes including the node serving as the root node and having a parent-child relationship among nodes of adjacent hierarchies, the node comprising:
a generating unit, implemented by processing circuitry, that generates a group key and a list indicating a specific node to which a distribution of the group key is inhibited; an encrypting unit that encrypts the group key to obtain an encrypted group key; and a transmitting unit that transmits, to the first child node, a first message including the encrypted group key and the list, wherein the encrypted group key is decryptable by a first child node of the root node, the first child node being a node other than the specific node, wherein the encrypting unit encrypts the group key using a shared key shared only between the root node and the first child node, and wherein after receipt of the first message including the encrypted group key and the list by the first child node, the list is accessed by the first child node in order to identify any nodes for which distribution of the group key is inhibited.