Patent ID: 9503257
Filing Date: 2016-11-22
CPC Classification: H04L

Claim Text:
1. A quantum key distribution device that is connected to another quantum key distribution device via a quantum communication channel and that generates and shares an identical encryption key with the another quantum key distribution device, the quantum key distribution device comprising: a quantum key sharing unit configured to generate a shared bit string by using quantum key distribution performed with the another quantum key distribution device via the quantum communication channel; a correcting unit configured to receive the shared bit string from the quantum key sharing unit and generate a corrected bit string through an error correction process with respect to the shared bit string; a compressor configured to receive the corrected bit string from the correcting unit and generate an encryption key through a key compression process with respect to the corrected bit string; a controller configured to perform a restraining operation in which the total number of bits of one or more encryption keys generated per unit time by the compressor is smaller than the total number of bits of the one or more encryption keys generated per unit time by the compressor in the case of not performing the restraining operation; wherein the controller is configured to adjust a restraining amount for the restraining operation based on a parameter related to the quantum key distribution device; the controller is configured to determine, based on a comparison between the parameter and a first threshold value, whether to perform the restraining operation; and the controller is configured to determine, based on a comparison between the parameter and a second threshold value, whether to stop the restraining operation.