Figure 4

A diagram of the key rate for two classical users to achieve key distribution. Observe that the protocol can work with noise less than 8.77%. Since we only adopt Alice and Bob both measure or both reflect events to calculate the critical parameters without exploiting the mismatched event, resulting in a lower key rate for our protocol than in [25] and [29]. If the same approach as in [25] and [29] is used, a key rate similar to that of [25, 29] can be achieved