NETWORK SYSTEM AND METHOD OF UPDATING SECRET SEED OF TERMINAL EQUIPMENT IN THE SAME

摘要

PROBLEM TO BE SOLVED: To substantially simultaneously perform switching from operation by secret seeds to operation by new secret seeds in all pieces of terminal equipment. SOLUTION: Application is employed to a network system in a hierarchy structure including a method of managing a cipher key for multicasting a communication message encrypted by allowing the terminal equipment and a server to use a key configuration based on their attributes. The network system includes: a new secret seed distribution means 1-1-1-1 for designating a utilization start time of the secret seed; a new secret seed reproduction means 1-2-1-1 for generating a new secret seed from a analysis secret key set to the terminal equipment; and a new secret seed validation means 1-1-1-2 for validating the utilization start time of the new secret seed set to the terminal equipment. COPYRIGHT: (C)2010,JPO&INPIT