Quantum key distribution protocol (QKDP)

                                Quantum key distribution is a technology which depends on the quantum physics laws and this is used for the production and distribution of cipher keys that are secure into few unsecured channels. Here photon technology identifies the third parties or eavesdroppers who try for probable eavesdropping in the quantum channels, for this the technology uses quantum bit errors. If the information is encoded and sent randomly then the single photon produces the distributed keys that are secure and secret. The estimation of probabilistic character and state of photon are estimated by the help of these distributed secret keys. Quantum key distribution system has two channels called quantum channel and classical channel. Quantum channel is used in the quantum key distribution system for transmission of qubits or single photons along a transparent optical path. Whereas the classical channel is paired strongly with the quantum channel in order to gain timing requirements and this classical channel is also considered as the usual IP channel.

                            There is much variation between the quantum cryptography and traditional cryptography because of the reason that laws of physics are concentrated more in quantum cryptography.  Particularly the data transmission and data saving in the quantum cryptosystem are done by using the laws of physics. For example, in a electric optical fiber, when the transmission of polarized photon is done then a secret key is created with help of optical fiber which can be considered as an secure channel. This secret key is generated in the form of a bits string that is random. These bit strings that are random are used in quantum cryptography in the same way like the secret keys are used in traditional cryptography. At present, many protocols for quantum key distribution are implemented, and these protocols are known as the B92 protocol, EPR protocol and two states protocol etc. The first implemented QKDP (Quantum key distribution protocol is called as BB84 protocol, this is designed by Gilles Brassard and Charles Bennet, this protocol is the most used protocol even now a days.

                    If we consider an example with two communication parties A and B, let A be the sender and B be the receiver and let the third party or eavesdropper be E. In this case of Quantum key distribution, the unconditional secure key should be distributed between A and B by noticing the existence of E. The security of QKDP is ensured differently with the help of quantum mechanics principles when it is regarded with the comparison to usual distributed key techniques which relies on the estimation of calculations that are yet to be verified. In usual techniques while the information is transferring the third parties cannot gain the knowledge of the data transferred because they don’t posses required resource to perform computations.

This Paper is written & submitted by Vamshidhar A.