Unique Cipher Mechanism for EnsuringSecure Data Flow over Network

Cryptography is the art of making text non readable from human readable to ensure secure communication over the network. It is classified basically into two types one is symmetric cryptography and the other is asymmetric cryptography. In the symmetric cryptography we use single key for encryption and decryption process which creates trouble of key sharing whereas in asymmetric cryptography two different keys are used for one for encryption and other for decryption which solves dependence on key sharing to large extent. But now traditional cryptographic ciphers are more prone to attacks and problem of authentication also exists as users have increased and few of them try to have unauthorized access. In order to solve this issue we have integrated biometric and visual cryptographic modules in the basic RSA module to make it more secure. The RSA encrypted text or message is hidden through LSB insertion in an image which also has shares of the fingerprint of the desired recipient. Along with that we have used the Caesar and mix columnar operation which protects RSA from man in middle attack as to decode the encoded text, attacker needs to know key used in mix columnar operation too. And as the size of text increases mix columnar becomes more effective. Moreover the receiver would be able to get the message only if his fingerprint matches to that of the desired one else he would just be able to see image only that is we have hidden the existence of secret message so as to make it even more secure. Matlab simulation has been carried out to validate the proposed technique