The quantum cryptography and the unambiguous measurement of quantum nonorthogonal states
Won Young Hwang, In Gyu Koh, Yeong Deok Han · arXiv (Cornell University) · 1997
We discuss the unambiguous measurement of quantum nonorthogonal states in connection with the quantum cryptography. We show that checking a ratio of null one to signal is essential in detecting a certain kind of eavesdropping in the case of two nonorthogonal states quantum cryptography. We prove that it is not needed in the case of the four states quantum cryptography.