US 12,231,553 B2
Key management device, quantum cryptography communication system, and computer program product
Yu Yu, Kawasaki Kanagawa (JP); Yasuhiro Katsube, Yokohama Kanagawa (JP); Yoshimichi Tanizawa, Yokohama Kanagawa (JP); Ririka Takahashi, Tokyo (JP); and Yasuhiro Fujiyoshi, Tokorozawa Saitama (JP)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (JP)
Filed by KABUSHIKI KAISHA TOSHIBA, Tokyo (JP)
Filed on Aug. 30, 2022, as Appl. No. 17/898,902.
Claims priority of application No. 2022-042596 (JP), filed on Mar. 17, 2022.
Prior Publication US 2023/0299952 A1, Sep. 21, 2023
Int. Cl. H04L 9/08 (2006.01)
CPC H04L 9/0855 (2013.01) 12 Claims
OG exemplary drawing
 
1. A key management device managing an application key for encrypting a communication in an application network including a plurality of applications, the key management device comprising:
one or more hardware processors configured to:
collect, using quantum key distribution (QKD), resource information indicating a resource of a link for which a link key is generated;
calculate metric for a key relay route including the link on a basis of the resource information;
determine a key relay route from among a plurality of key relay routes on a basis of the metric; and
use the key relay route determined to send, to a destination, an application key encrypted with the link key,
wherein
the resource information includes at least one of a generation speed for the link key in the link and an amount of the link key held in the link, and
the one or more hardware processors:
calculate first metric based on a bottleneck of resource information on a plurality of links included in the key relay route, the bottleneck being determined based on costs of the plurality of links, the costs each being one of a generation speed for the link key of corresponding one of the plurality of links, an amount of the link key held in the corresponding one of the plurality of links, and a weighted sum of the generation speed for the link key and the amount of the link key; and
determine the key relay route using the first metric as the metric.