Inconclusive rate as a disturbance measure in quantum cryptography
Howard E. Brandt · Physical Review A · 2000
The inconclusive rate is considered as a disturbance measure in key distribution in quantum cryptography. Bennett's two-state protocol is addressed for the case in which a positive operator-valued measure is implemented by the legitimate receiver in the presence of an individual attack by a general unitary disturbing eavesdropping probe. The maximum Renyi information gain by the disturbing probe is calculated for given receiver error and inconclusive rates. It is demonstrated explicitly that less information is available to an eavesdropper at a fixed inconclusive rate and error rate than is available at a fixed error rate only.