Encryption key update method , encryption key update equipment , and encryption key update program

摘要

PROBLEM TO BE SOLVED: To securely distribute an updated key only within a group.;SOLUTION: For example, a new key (k'2, 2) of a group (G2, 2) are encrypted and multicasted by using hash values for splicing connection between an encryption key of the group (G2, 2) and an encryption key of a group (G0, 1). A group head of the group (G2, 2) receives and transfers these keys to nodes other than a node (n). Thus, the node (n) is excluded from the group (G2, 2).;COPYRIGHT: (C)2013,JPO&INPIT