| 摘要 |
PROBLEM TO BE SOLVED: To improve message inspection performance in a communication network system in which a transmission node is connected with a reception node.SOLUTION: A transmission node and a reception node store the same secret information in their respective secret information storage units 117. The transmission node keeps a transmission counter value which is increased by one per message transmission in a counter unit 115, generates a MAC by a MAC generation unit 114 on the basis of transmission data, the transmission counter value, and the secret information, and transmits a message including the transmission data and the generated MAC. The reception node keeps a reception counter value which is increased by one per message reception in a counter unit 115, generates a MAC by a MAC inspection unit 116 on the basis of reception data obtained from a reception message, the reception counter value, and the secret information, and inspects by the MAC inspection unit 116 whether the generated MAC accords with the MAC obtained from the reception message. |
