Practical scheme to share a secret key through a quantum channel with a 27.6% bit error rate
H. F. Chau · Physical Review A · 2002
A secret key shared through quantum key distribution between two cooperative players is secure against any eavesdropping attack allowed by the laws of physics. Yet, such a key can be established only when the quantum channel error rate due to eavesdropping or imperfect apparatus is low. Here, a practical quantum key distribution scheme by making use of an adaptive privacy amplification procedure with two-way classical communication is reported. Then, it is proven that the scheme generates a secret key whenever the bit error rate of the quantum channel is less than $0.5\ensuremath{-}0.1\sqrt{5}\ensuremath{\approx}27.6%,$ thereby making it the most error resistant scheme known to date.