A hybrid cryptosystem of image and text files using blowfish and Diffie-Hellman techniques

In this paper we have proposed a new algorithm of encrypting and decrypting images and text files. The proposed method is implemented by combining the concepts of Diffie Hellman algorithm and Blowfish algorithm. In this new technique at first a computer user will encrypt a file using a secret key generated by blowfish algorithm. Then using Diffie-Hellman protocol a shared private key will be generated for two computer users who are trying to communicate over an insecure channel. Now if the second user wants to decrypt the file encrypted by the first user he/she has to use the shared key for permission. Once the permission is granted, the file can be decrypted using blowfish algorithm.