An Adaptive Use of Deffie Hellman Algorithm by Digital Images for Generating Secure Shared Key

Security is one of the most imperative commentaries in contemporary era. Especially, in terms of creating a safe channel. Create secure channel means the protection of information against an invader during exchanging the data through channel. Many procedures suggested overcoming this problem like cryptography, steganography, biometrics. etc. In this paper, the propose system consist of two stages the first is generated key called image key from an image while the second stage is applied Diffie Hellman based on the key which is created from the first step. The image key in our system is used instead of the two numbers which are needed compulsory in Hilleman algorithm. In our proposal two client will not need to agree previously about the two numbers (prime and integer) which are basically the requirements in d, h algorithm to generate the shared key which should be used in ciphering process in advance. Moreover, the exchange key as a part of Diffie Hellman algorithm will be exchanged between parties through hiding it in own copy image of each party in specific position which are selected based on image key that are created in the first stage. The hiding process support a secure channel for two parties to exchange their keys securely. Moreover, support securely channel is done with keeping quality of stego- image due to limitation pixels which are used for hiding process. in addition the hiding process is applied in high bit plane 8th lsb to make it immune against channel effected like noise or compression. The system has been proved truly and the image key generated completely and exchange keys exchanged truly even if the channel has some effect on image like noise or compression.