| 摘要 |
PROBLEM TO BE SOLVED: To solve the problems that an arithmetic unit with a large circuit scale due to software is required in the conventional manner for encryption and decryption and that authentication time becomes long because time for arithmetic operations is required. SOLUTION: Before a transmitter transmits main information to a receiver, first, the receiver transmits a first random number to the transmitter, a synchronizing signal and key information are generated on the basis of the first random number received by the transmitter, and a composite signal obtained by embedding both the key information and the synchronizing signal in a third random number is transmitted to the receiver (steps S1 to S5). The receiver acquires the key information from the received composition signal, generates, and stores a second cryptographic key on the basis of the key information and then transmits an acknowledgment to the transmitter (steps S6 to S8). The transmitter generates a first cryptographic key on the basis of the key information. This enables the transmitter and the receiver to share the cryptographic key each other by simple and small-scale hardware without using a special arithmetic unit. COPYRIGHT: (C)2005,JPO&NCIPI
|
