Image Encryption using Sub Matrix Substitution Cipher Technique

Abstract

Now a days, Information Security plays an important role in this modern world.  With the global usage of the Internet, virtually world is interconnected to each other, while it has created a lot of risks to the users who are involved in it. The users, businesses and organizations worldwide are suffering from a continuous problems from attackers and hackers, who have a variety of tools and techniques in order to break the secret information and make changes to the data, which leads to security issues. One of the most important aspect is transmission of message such as text, image over the network securely. Many cryptographic algorithms have been proposed for secured transmission so that no other person can gain the access of transmitted data. The Encryption algorithm plays an important role to transmit data through the network. In this paper, an image data is considered, generally each and every pixel is encoded with a secret key and transmitted and decrypted at the receiver side. In some algorithms, the blocks of pixels are encoded with different keys.  In this paper a new methodology introduced to perform the encryption with some variation in substitution cipher algorithm on split sub matrices with different keys instead of sequence block of pixels.  In this paper, the proposed algorithm is applied for both text and image data to know the performance in terms of speed.  By applying this methodology, it increases the security a lot for the information and can be easily transmitted in the network