Key management server device, QKD system, and key management method

A QKD system comprising:

• a plurality of first key generation nodes that generate quantum key distribution (QKD) keys generated through a key distillation process for QKD;
• a first key management server device that is connected to the plurality of first key generation nodes;
• a plurality of second key generation nodes that generate QKD keys through a key distillation process for QKD;
• and
• a second key management server device that is connected to the plurality of second key generation nodes and to the first key management server device, wherein
• the first key management server device includes:
• processing circuitry configured to
• receive the QKD keys from the plurality of first key generation nodes, and stores the QKD keys in a plurality of memories corresponding to the plurality of first key generation nodes;
• identify QKD keys to be specified as targets for shaping with the second key management server device, by exchanging identification information of the QKD keys with the second key management server device;
• based on the identification information of the QKD keys, perform numbering for each first key generation node in such a way that an order of the QKD keys in the first key management server device is identical to an order of QKD keys in the second key management server device;
• and
• perform shaping processing for shaping key lengths of the QKD keys to a fixed length by performing division of a QKD key or coupling of a QKD key with a part of a QKD key that is not used in the previous shaping processing in the order of the QKD keys in the first key management server device.

A key management method comprising:

• receiving, by a key management server device, from a plurality of key generation nodes, quantum key distribution (QKD) keys generated through a key distillation process for QKD, and storing the QKD keys in a plurality of memories corresponding to the plurality of key generation nodes;
• identifying, by the key management server device, QKD keys to be specified as targets for shaping processing with a partner key management server device by exchanging identification information of the QKD keys with the partner key management server device;
• performing numbering, by the key management server device, based on the identification information of the QKD keys, in such a way that an order of the QKD keys in the key management server device is identical to an order of QKD keys in the partner key management server device;
• and
• performing shaping processing, by the key management server device, for shaping key lengths of the QKD keys to a fixed length by performing division of a QKD key or performing coupling of a QKD key with a part of a QKD key that is not used in previous shaping processing in the order of the QKD keys in the key management server device.