KEY SETTING METHOD, NODE, SERVER AND NETWORK SYSTEM

摘要

A node (N1a) of an ad-hoc network (A1) receives an encrypted GW search frame group (K (TF)) from a new node (Nx). Because encrypted GW search frames (K2 (TF)-(K4 (TF)), which have been encrypted using encryption keys ((K2)-(K4)), cannot be decrypted using an encryption key (K1), the encrypted GW search frames are discarded at the node (N1a). By contrast, an encrypted GW search frame (K1 (TF), which has been encrypted using the encryption key (K1) can be decrypted at the node (N1a). Thus, the encrypted GW search frame (K1 (TF)) is transmitted by means of multipop communication within the ad-hoc network (A1). A gateway (G1) receives the encrypted GW search frame (K1 (TF)) that has been transmitted from the node (N1a) by means of the multipop communication within the ad-hoc network (A1). The gateway (G1) generates a key notification frame (NF1) and transmits the key notification frame to an administrative server (101) via a network (NW1).