| CPC H04L 9/0852 (2013.01) [G06F 1/12 (2013.01); G06N 10/60 (2022.01); H04B 10/70 (2013.01); H04L 9/0819 (2013.01); H04L 9/085 (2013.01)] | 10 Claims | 

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               1. A quantum key distribution method for distributing a secret key over a quantum communication channel between a transmitter and a receiver, the method comprising the steps of: 
            synchronizing a clock between the transmitter and the receiver, wherein the clock is a digital value, binary encoded on a plurality of bits from a least significant bit to a most significant bit, 
                distributing the secret key from the transmitter to the receiver, wherein the synchronizing step comprises: 
              a first transmitting step for transmitting a N-th bit of the clock from the transmitter to the receiver, 
                  a second transmitting step for transmitting acknowledgement of reception of the N-th bit from the receiver to the transmitter, 
                  a first checking step for checking if the N-th bit is the most significant bit of the clock, and 
                  an incrementing step for incrementing the value of N if the first checking step indicates that the N-th bit is not the most significant bit of the clock. 
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