CRYPTOGRAPHIC KEY CONFIRMATION DEVICE

摘要

PROBLEM TO BE SOLVED: To allow a cryptographic key confirmation device that can make a simultaneous notice to a plurality of terminals to confirm a revised group communication cryptographic key at a high-speed. SOLUTION: In a terminal 1, a bit exchange section 16 revises a bit position of a communication cryptographic key extracted from a memory 14 and a ciphering/decoding section 13 uses a key delivery cryptographic key to cipher the communication cryptographic key. A bit selection section 15 selects and extracts a prescribed bit from the communication cryptographic key and transmits the bit to a collation re-transmission section 31 of a base station 2. The base station 2 conducts a similar arithmetic operation and gives the obtained information to the collation re-transmission section 31. The collation re-transmission section 31 compares the information sent from the terminal 1 with the information of the base station 2. When they are dissident, it is discriminated that the communication cryptographic key possessed by the terminal 1 is in error and processing such as re-transmission of the communication cryptographic key is conducted.