A quantum key distribution device connectable to another quantum key distribution device through a quantum communication channel to share an encryption key, the quantum key distribution device comprising: a common processing unit configured to output intermediate data based on bit information obtained by transmitting or receiving sequence of photons with the another quantum key distribution device through the quantum communication channel; two or more individual processing units, each individual processing unit generating or providing the encryption key in accordance with the intermediate data, the two or more individual processing units being set with mutually different parameters and variations; and a distribution unit configured to distribute the intermediate data that is output from the common processing unit to two or more distribution destination that include the individual processing units, wherein the common processing unit comprises: a quantum key sharing unit configured to acquire a photon bit string corresponding to the sequence of photons transmitted or received through the quantum communication channel; and a first key distillation processing unit configured to output the intermediate data by executing partial processing of key distillation processing based on the photon bit string, and each individual processing unit comprises a second key distillation processing unit (103a to 103c, 104a to 104c) configured to generate the encryption key by executing remaining of the key distillation processing excluding the partial processing based on the intermediate data distributed from the distribution unit. a common processing unit configured to output intermediate data based on bit information obtained by transmitting or receiving sequence of photons with the another quantum key distribution device through the quantum communication channel; two or more individual processing units, each individual processing unit generating or providing the encryption key in accordance with the intermediate data, the two or more individual processing units being set with mutually different parameters and variations; and a distribution unit configured to distribute the intermediate data that is output from the common processing unit to two or more distribution destination that include the individual processing units, wherein the common processing unit comprises: a quantum key sharing unit configured to acquire a photon bit string corresponding to the sequence of photons transmitted or received through the quantum communication channel; and a first key distillation processing unit configured to output the intermediate data by executing partial processing of key distillation processing based on the photon bit string, and a quantum key sharing unit configured to acquire a photon bit string corresponding to the sequence of photons transmitted or received through the quantum communication channel; and a first key distillation processing unit configured to output the intermediate data by executing partial processing of key distillation processing based on the photon bit string, and each individual processing unit comprises a second key distillation processing unit (103a to 103c, 104a to 104c) configured to generate the encryption key by executing remaining of the key distillation processing excluding the partial processing based on the intermediate data distributed from the distribution unit.