Quantum Cryptography

Quantum Cryptography

Transmitting information with access restricted to the intended recipient even if the message is intercepted by others.Cryptography is of increasing importance in our technological age using broadcast, network communications, Internet ,e-mail,cell phones which may transmit sensitive information related to finances, politics, business and private confidential matters.

Elements of the Quantum Theory

1. Light waves are propagated as discrete quanta called photons.
2. They are massless and have energy, momentum and angular momentum called spin.
3. Spin carries the polarization.
4. If on its way we put a polarization filter a photon may pass through it or may not.
5. We can use a detector to check of a photon has passed through a filter.

Ref it...,
http://www.box.net/shared/za2cmflrmj