DATA TRANSCEIVING SYSTEM, ENCRYPTED INFORMATION TRANSMISSION METHOD, DATA TRANSMISSION APPARATUS, AND DATA RECEIVER

摘要

PROBLEM TO BE SOLVED: To irregularly perform the update of an encryption key without increasing a load of a communication system. SOLUTION: A mobile communication system 1 adopting ROHC (RObust Header Compression) is characterized by including: a first communication data creation unit 120 which creates a part to be memorized (a first communication data) in a context memory unit 23 out of packet headers including an unchanged field whose content does not change during continuation of data transmission and an encryption key field including an encryption key; and an encrypted information acquisition unit 24 which acquires the encryption key from the encryption key field included in the packet (composite communication data) received by a base station apparatus 20. COPYRIGHT: (C)2007,JPO&INPIT