Alice generates a sequence of key bits forming an initial cryptographic key. Alice then uses the sequence of key bits and a sequence of cipher bits to control respective control parameters of a quantum encoding process applied to a sequence of quantum pulses, where the sequence of cipher bits used is known to Bob. Alice then releases the encoded pulses towards Bob over a quantum channel. Bob uses the previously agreed-upon sequence of cipher bits to control a control parameter, such as the quantum basis, of a quantum detection process applied to the pulses received from Alice, thus producing a detection outcome for each received pulse. Bob then derives a final cryptographic key from the detection outcomes. Because the cipher bits used to select the quantum bases used by both Alice and Bob are known by both parties, the method allows the final cryptographic key to be distributed with full basis alignment compared to 50% for BB84, thus allowing efficient quantum key distribution over multiple hops.