A Study on the Movement of Office Location in the Center of Tokyo

Secure key rate of the BB84 protocol using finite sample bits

“…This is because the asymptotic limit of the accurate channel estimation is much larger than the conventional one, as shown in [30], while the accurate channel estimation also experiences the degradation from the increased number of parameters with smaller sample sizes as well. Since the asymptotic limit of the accurate channel estimation is always larger than the conventional one if the channel is not a Pauli one [29], the accurate channel estimation is expected to work better when the channel is supposed to be non-Pauli and the sample size for channel estimation is large.…”

“…In contrast, Watanabe et al [30] show that by using the statistics of mismatched measurement outcomes in addition to that of matched measurement outcomes, we can estimate a quantum channel more accurately, thereby the key rate is at least higher than the conventional one. In particular, the key rate is generally improved over the conventional one over any channel, and only if the quantum channel is the Pauli channel, those two key rates are equal [29].…”