A quantum communication device comprising: a corrector (24; 24-1) configured to generate corrected key data by performing error correction on received key data received from a transmitting device through a quantum channel; and a retransmission controller configured to transmit a retransmission request including retransmission target address information to the transmitting device through a control channel when a retransmission request condition is satisfied, and receive retransmission key data corresponding to the retransmission target address information from the transmitting device through the control channel, characterized in that the corrector (24; 24-1) divides the received key data into a plurality of error correction blocks and performs error correction on each error correction block, the corrector is a low-density parity-check decoder configured to output information indicating success or failure in error correction on each error correction block, corrected key data of each error correction block, and reliability of data included in the corrected key data, the retransmission target address information indicates an address of data the reliability of which is below a threshold, the data being included in an error correction block that has been unsuccessfully error corrected, and after receiving the retransmission key data, the corrector (24; 24-2) replaces corrected key data corresponding to the retransmission target address information with the retransmission key data to generate replaced data, and performs error correction on the replaced data. a corrector (24; 24-1) configured to generate corrected key data by performing error correction on received key data received from a transmitting device through a quantum channel; and a retransmission controller configured to transmit a retransmission request including retransmission target address information to the transmitting device through a control channel when a retransmission request condition is satisfied, and receive retransmission key data corresponding to the retransmission target address information from the transmitting device through the control channel, characterized in that transmit a retransmission request including retransmission target address information to the transmitting device through a control channel when a retransmission request condition is satisfied, and receive retransmission key data corresponding to the retransmission target address information from the transmitting device through the control channel, characterized in that the corrector (24; 24-1) divides the received key data into a plurality of error correction blocks and performs error correction on each error correction block, the corrector is a low-density parity-check decoder configured to output information indicating success or failure in error correction on each error correction block, corrected key data of each error correction block, and reliability of data included in the corrected key data, the retransmission target address information indicates an address of data the reliability of which is below a threshold, the data being included in an error correction block that has been unsuccessfully error corrected, and after receiving the retransmission key data, the corrector (24; 24-2) replaces corrected key data corresponding to the retransmission target address information with the retransmission key data to generate replaced data, and performs error correction on the replaced data. <EOS>