ENCRYPTION KEY DELIVERY DEVICE AND ENCRYPTION KEY DELIVERY METHOD

摘要

It is possible to provide an encryption key delivery device and an encryption key delivery method capable of maintaining security intensity and performing reliable and flexible communication. A generation unit formed by a fist phase key mixer (210) and second phase key mixers (221-223) generates a packet encryption key for each of packets to be transmitted to a plurality of radio reception terminals by multicast or broadcast so as to encrypt the packet. A packet encryption key holding unit (220) holds a plurality of packet encryption keys generated by the generation unit for a plurality of continuous packets. A packet encryption key delivery unit (260) delivers any one of the packet encryption keys held by the packet encryption key holding unit (220) to one of the radio reception terminals independently of the packet transmitted by multicast or broadcast.