Introduction

                  The general security task that is developed for huge number of network security systems is called Cryptography. There are several cryptographic techniques that are used for the security task, and Quantum cryptography is one of the techniques which are used mostly. Quantum mechanics are specifically used by the quantum cryptography. The general and most significant task in cryptography is the distribution of keys; this process includes a monotonous job that is to guarantee the security of distribution of keys. In quantum cryptography the procedure of photon transmission is used by the participating device which is similar to the procedure of light emission. And the data packet in the quantum cryptography is transmitted as a photon and the transmission status is decided by the state of photon. Quantum cryptography enables communication between the new parties and provides comfort and security even if the parties participating are new to one another.

This Security in Large Networks is because of the reason that data transmission using quantum cryptography is done more securely. Generally in all the cryptographic techniques, security of the data depends on the decryption process and encryption process designed and implemented. Now a day in these encryption and decryption processes, coding the algorithm is done by chippers. These chippers are considered as the key process, chippers are mad e of some special parameters generally referred as KEY and both communication parties are provided with these keys as inputs for the algorithms of encryption and decryption. The entire security is based on the distributed key as the encryption and decryption algorithms are publicly announced and thus to guarantee the security and that particular key must have n number of bits and should be generated at random and sufficiently lengthy.

The key is distributed to the communication process when once it gets generated and this process of distribution is possible by a public channel. This process of distribution is not recommended in all the cases as there is a possibility for eavesdropping like mass media and these types of issues can be handled by mathematical accomplishment. Generally in traditional cryptography eavesdroppers are prevented from understanding the data encrypted in messages by using different mathematical techniques. But in case of quantum cryptography implementation is done with physics laws but not with the mathematical techniques. But comparatively quantum cryptography gives most secure communication when compared to the classical cryptography.

                      Identifying the third party in a communication process is identified by the quantum cryptography which is regarded as the significant feature in this type of cryptography. Not only detecting the third parties preventing them to access the information of the key by the other two parties involved in communication process. This identification procedure includes quantum entanglement or quantum superposition along with the basic quantum mechanics. By using these procedures the eavesdroppers are identified and prevented to such activities like mass media and also help in transmitting the data through quantum states. The quantum states those transmits data are generally called as qubits which are entirely converse for the bits used in general cryptography. Generally these qubits are generated by using photons. Secure communication process is guaranteed in quantum cryptography using the quantum states. 

This Paper is written & submitted by Vamshidhar A.