Communication device, communication system, and computer program product

摘要

According to an embodiment, a communication device is connected to a plurality of external devices which share key information with each other. The communication device includes a detector and an instructing unit. The detector is configured to, from among the external devices, detect an external device that has been subject to attack. The instructing unit is configured to issue an instruction to stop using key information which is shared with the detected external device.

主权项

1. A communication device that is connected to a plurality of external devices sharing key information, the communication device comprising:
a sharing operation unit configured to continue to share the key information with one or more of the plurality of external devices using quantum key distribution technology; a key storage memory configured to differently store the shared key information depending on one of the type of key information and the one or more of the plurality of external devices participating in the sharing; a detector configured to, from among the one or more of the plurality of external devices, detect an external device that has been subject to attack; and responsive to determining the detected external device is subject to attack, an instructing unit configured to issue an instruction to stop using the shared key information which is stored by the key storage memory and shared with the detected external device, wherein the instructing unit further issues an instruction to stop the sharing operation unit from sharing the shared key information with the detected external device, and further issues an instruction to set to an unusable state the shared key information that is stored by the key storage memory and shared with the detected external device, wherein responsive to determining the attacked external device has been restored to a secure status, the instructing unit further issues an instruction to restart the sharing operation to share the shared key information with the restored external device and further issues an instruction to set the shared key information that is shared with the restored external device and stored by the key storage memory to a usable state and resume using the shared key information.