Manage your account and access personalized content. Access your cloud dashboard, manage orders, and more. This is used to detect eavesdropping what is cryptography pdf quantum key distribution. This simply means that observation of quanta changes its behavior.
The No-cloning theorem demonstrates that it is impossible to create a copy of an arbitrary unknown quantum state. This makes unobserved eavesdropping impossible because it will be quickly detected, thus greatly improving assurance that the communicated data remains private. Columbia University in New York, who, in the early 1970s, introduced the concept of quantum conjugate coding. In this paper he showed how to store or transmit two messages by encoding them in two “conjugate observables”, such as linear and circular polarization of light, so that either, but not both, of which may be received and decoded. He illustrated his idea with a design of unforgeable bank notes.