Quantum cryptography communication control device, quantum cryptography communication system, quantum cryptography communication control method, and computer program product

A quantum cryptography communication system comprising:

• a plurality of nodes;
• and
• a central management node, wherein
• the plurality of nodes includes
• a first collection unit configured to collect link information of a link for which a local key is generated by quantum key distribution and a guaranteed amount of a global key for each of a plurality of application pairs executing cryptography communication using a global key, and
• the central management node includes
• a second collection unit configured to collect the link information and guaranteed amounts of global keys collected by the plurality of nodes,
• a calculation unit configured to calculate a link cost used for selecting a relay route of the global key based on the link information,
• a guarantee amount calculation unit configured to calculate a guaranteed amount of a local key allocated to the link for relaying the global key of each of the plurality of application pairs such that the guaranteed amounts of the global keys for the plurality of application pairs are simultaneously satisfied, and
• a selection unit configured to select the relay route of the global key based on the link cost and the local key guarantee amount.

A quantum cryptography communication control method implemented by a computer of a quantum cryptography communication control device, the method comprising:

• collecting link information of a link for which a local key is generated by quantum key distribution and a guaranteed amount of a global key for each of a plurality of application pairs executing cryptography communication using a global key;
• calculating a link cost used for selecting a relay route of the global key based on the link information;
• calculating a guaranteed amount of a local key allocated to the link for relaying the global key of each of the plurality of application pairs such that guaranteed amounts of the global keys for the plurality of application pairs are simultaneously satisfied;
• and
• selecting the relay route of the global key based on the link cost and the local key guarantee amount.