NODE DEVICE AND PROGRAM

摘要

In a first apparatus in a network constituted by a plurality of node apparatuses, an access key generation unit changes a first access key being a cryptographic key unique to the first node apparatus at intervals of the first time. A shared key generation unit changes a shared key being the same for the plurality of node apparatuses at intervals of a second time. The first node apparatus encrypts, using the generated shared key, the generated first access key and transmits it, and receives an access key notification frame that is transmitted from the second node apparatus and that includes data obtained by encrypting a second access key of a second node apparatus using the shared key. A decryption unit obtains the second access key by decrypting the received access key notification frame using the generated shared key. A transmission unit transmits an encrypted frame obtained by encrypting, using the second access key, a plaintext frame to which signature data obtained by encrypting data including a hash value calculated from the plaintext frame by the shared key is attached.