Quantum Chinese Magic Box

Abstract: This work introduces a new concept of Chinese-Magic-Box. The general idea is to have a box such that the sender can store information in multiple drawers. The receiver is free to open any drawer. However, once the receiver opens the drawer, he can retrieve the information from that drawer only, that is, the information that was stored in the other drawers is lost. This property is achieved by storing the information using a set of non-orthogonal quantum states. The different drawers are realized by different orthogonal set of basis for the measurement. Once the measurement is performed, the information in this basis is retrieved. At the same time, due to wave function collapse the information in the other basis is lost and cannot be retrieved. I show how to construct a set of states for a single qubit to implement a Box with two or three drawers. Some applications are discussed. Among them is a new non-symmetric Quantum Key Distribution with only single direction classical communication.