Information processing device, qkd network system, information processing method, and computer program product

An information processing method implemented by a computer of an information processing unit, the method comprising:

• establishing encrypted tunnel communication with a second node by using a second encryption key subjected to encrypted relay transmission to the second node by a first encryption key shared, by quantum key distribution, with a plurality of first nodes adjacent to each other, the second node being one of the plurality of first nodes;
• and
• transferring a third encryption key to the second node by the encrypted tunnel communication.

A computer program product having a non-transitory computer readable medium including programmed instructions stored thereon, wherein the instructions, when executed by a computer, cause the computer to:

• establish encrypted tunnel communication with a second node by using a second encryption key subjected to encrypted relay transmission to the second node by a first encryption key shared, by quantum key distribution, with a plurality of first nodes adjacent to each other, the second node being one of the plurality of first nodes;
• and
• transfer a third encryption key to the second node by the encrypted tunnel communication.