Today Communication is mainly depends upon digital data communication. Data is sent across internet using sequence of bits. Data integrity is major issue in such a communication. To preserve data integrity of the message sent over the internet various method of cryptography is used. Though there are two types of algorithm for encryption namely symmetric [1] and asymmetric [1], This paper is mainly concern with digital symmetric cryptography using image to replace some bits and at the receiver side this encrypted message is decrypted at the receiver side For Encryption block cipher mode [2] is used which is data is encrypted in blocks rather than individual bits. Digital encryption of data is the approach, in which the original data, say x, is first digitized into a sequence of bits, x (k) which are then embedded digitally with the chosen segments of the image file, y (k) before transmission. For this, we have utilized the MATLAB (Matrix-Laboratory) which is a multi-paradigm numerical computing environment and fourth generation programming language. Encryption is a much stronger method of protecting speech communications than any form of scrambling. The ability to securely store and transfer sensitive information has proved to be a critical factor of success in today's day and age. The secrecy as well as integrity of data during storage and transmission has been the motivating factor for us in the build up to this paper.