Synopsis

1. PROBLEM STATEMENT

This project attempts to make use of the standard steganographic tool and a modified version of standard encryption algorithm to perform the task of data hiding for the purpose of observing privacy. The user should be able to conceal a text message in an image file without any visible alterations to the image as such i.e. there should not be any noticeable changes to the coloring or the position of the various objects in the image.

2. INTRODUCTION

Since the rise of the Internet one of the most important factors of information technology and communication has been the security of information. Cryptography was created as a technique for securing the secrecy of communication and many different methods have been developed to encrypt and decrypt data in order to keep the message secret. Unfortunately it is sometimes not enough to keep the contents of a message secret, it may also be necessary to keep the existence of the message secret. The technique used to implement this, is called steganography.

Steganography is the art and science of invisible communication. This is accomplished through hiding information in other information, thus hiding the existence of the communicated information. The word steganography is derived from the Greek words “stegos” meaning “cover” and “grafia” meaning “writing” defining it as “covered writing”. In image steganography the information is hidden exclusively in images.

Steganography differs from cryptography in the sense that where cryptography focuses on keeping the contents of a message secret, steganography focuses on keeping the existence of a message secret. Steganography and cryptography are both ways to protect information from unwanted parties but neither technology alone is perfect and can be compromised. Once the presence of hidden information is revealed or even suspected, the purpose of steganography is partly defeated. The strength of steganography can thus be amplified by combining it with cryptography.

Fig 1 : Context Diagram of Steganography

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Synopsis

3. LITERATURE SURVEY

Piyush Marwaha, et al[2010][1], Visual steganography is one of the most secure forms of steganography available today. It is most commonly implemented in image files. However embedding data into image changes its color frequencies in a predictable way. To overcome this predictability, we propose the concept of multiple cryptography where the data will be encrypted into a cipher and the cipher will be hidden into a multimedia image file in encrypted format. We shall use traditional cryptographic techniques to achieve data encryption and visual steganography algorithms will be used to hide the encrypted data.

Amitabh Mishra, et al [2009][2], Steganography can be implemented using a new technique. This technique uses LSB steganography as the basis and randomly disperses the secret message over the entire image to ensure that the secret message cannot be obtained easily from the image. Detailed visual and statistical analysis of the algorithm reveals that it yields satisfactory results. When compared with other existing algorithms, it is easy to prove that the difficulty of decoding the proposed algorithm is high.

Ke ZHANG, et al[2009][3], As the extension of the least significant bits(LSB) steganographic algorithm, steganographic algorithm embedding in two least-significant bits (Two-LSBs for short) has some characteristics, such as visual imperceptibility, higher capacity and easy realization. A new steganalysis method is introduced to detect the existence of hidden message that are randomly embedded in LSB and the second significant bits (second-LSBs)of image pixels. It is proposed based on investigating the statistical characters of image data in LSB and the second significant bits with hidden message.

Mamta Juneja, et al [2009][4], A new approach has been proposed for the design of a Robust image steganography which involves LSB (Least Significant Bit) insertion and RSA encryption technique. Steganography is the term used to describe the hiding of data in images to avoid detection by attackers. Steganalysis is the method used by attackers to determine if images have hidden data and to recover that data. The application discussed in this paper ranks images in a users library based on their suitability as cover objects for some data. By matching data to an image, there is less chance of an attacker being able to use steganalysis to recover the data. Before hiding the data in an image the application first encrypts it. The steganography method proposed inthis paper and illustrated by the application is superior to that used by current steganography tools.

Venkatraman.S, et al [2004][5], With the ever increasing amount and variety of data to be stored and transmitted in various mediums, the specification of security which has to be established at various levels of medium access and the accompanying issues of authentication and authorization has become a critical factor. Various steganographic, watermarking and data-embedding algorithms have usually manipulated the actual data in order to either hide any coveted information or to provide some level of access control over the medium. The mediums are usually images, video, audio etc., wherein specific

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Synopsis

portions or the overall space is usually ‘corrupted’ with ‘significant’ data. This paper is an attempt to bring out the significance of the steganographic techniques that are employed in information processing algorithms for data security. It deals with the problem of data security, focusing mainly on images, and tries to state the various properties and characteristics that the steganographic algorithms should possess. The paper also highlights the technique of masking used in the conventional steganographic LSB algorithms and in its variants.

R.Chandramouli, et al [2001][6], there have been many techniques for hiding messages in images in such a manner that the altercations made to the image are perceptually indiscernible. However the question whether they result in images that are statistically indistinguishable from untampered images has not been adequately explored.In this paper we look at some specific inage based steganography techniques and show that an observer can indeed distinguish between images carrying a hidden message and images which do not carry a message.We derive a closed form expression of the probability of detection and false alarm in terms of the number of bits that are hidden. This lead us to the notion of steganographic capacity,that is, how many bits can we hide in a message without causing statistically significant modification? Our results are able to provide an upper bound on this capacity. Our ongoing work relates to adaptive steganographic tecniques that take explicit steps to foil the detection mechanism.In this case we hope to show that the number of bits that can be embeded increases significantly.

K Suresh Babu, et al [2001][7], Steganography and Steganalysis are two important areas of research that involve a number of applications. These two areas of research are important especially when reliable and secure information exchange is required. Steganography is an art of embedding information in a cover image without causing statistically significant variations to the cover image. Steganalysis is the technology that attempts to defeat Steganography by detecting the hidden information and extracting. In this paper we propose an image Steganography that can verify the reliability of the information being transmitted to the receiver. The method can verify whether the attacker has tried to edit, delete or forge the secret information in the stego-image.

4. PROPOSED METHOD

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Synopsis

The Proposed method here is Object Oriented analysis. Object oriented analysis is basically concerned with the decomposition of a problem into its component parts and establishing a logical model to describe the system functions. We follow this analysis as for the project.

Object Oriented Analysis ( OOA ) approach consists of the following steps :

4.1 Understanding the problem :

This is the first step in the analysis process. The problem statement provides the basis for drawing the requirements specification of both the user and the software .

4.2 Requirements Specifications :

Once the problem is clearly defined , the next step is to understand what the proposed to do. Based on the user requirements , the specification for the software should be drawn . The developer should state clearly

What outputs are required ? A set of screens displaying the output of data hiding and retrieval of hidden data .

What inputs are necessary ?Various interactive inputs that take the user through the different stages encountered during the execution of the application .

What processes are involved to produce these outputs ?Entering the text , choosing the picture , encoding , decoding display .

4.3 Identification of objects :

Objects can often be identified in terms of the real world objects as well as the abstract objects. Their applications can be best analyzed by using the data flow diagrams. Design is concerned with the mapping of objects in the problem space into objects in the solution space and creating an overall structure and computational models for the system. This stage normally uses the bottom - up approach to build the structure of the system and the top- down functional decomposition approach to design the class member functions that provides services. The steganographic process basically involves encoding, decoding and checking if encodable. These are the basic functions of the class codec and the pic codec class. The encryption process is handled by the crypt and objects .The remaining objects are the various dialogs for display and interaction with the user.

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Synopsis

Fig 2 : A Steganography System

The above diagram consists of the following parts : Message File: This is the file to be encrypted. Cover File: This is the image file that is used for encryption. Steg File: This is the result of encrypting message file with cover file. Steganography Tool: This tool allows users to insert and extract hidden data into and

from steg files.

5. APPLICATIONS

Web based applications Steganographic Printers Intelligence Services Digital Watermarking Defence

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6. REFERENCES

1. Visual Cryptographic Steganography in Images, Piyush Marwaha1, Paresh Marwaha2, Infosys Technologies Limited, India

2. Proposal of a New Steganographic Approach, Amitabh Mishra , Akshay Gupta, D.K. Vishwakarma, Department of Electronics & Communication Engineering, ASET, Amity University, India

3. Stegananlysis Method of Two Least-Significant Bits Steganography Ke ZHANG Hai-ying GAO Wan-su BAO Zhengzhou Information Science and Technology Institute, Zhengzhou, 450004,China

4. Designing of Robust Image Steganography Technique Based on LSB Insertion and Encryption Mamta Juneja, Parvinder Singh Sandhu, Department of Computer Science and Engineering, Rayat and Bahra Institute of Engineering and Bio-Technology, Punjab Technical University, Punjab, India

5. Significance of Steganography on Data Security Venkatraman.S, Ajith Abraham, Marcin Paprzycki, Dept. of Computer Science & Engineering, University of Madras, India

6. Analysis of LSB Based Image Steganography Techniques, R Chandramouli, MSyNC Lab, Stevens Institute Of Technology, Dept. Of Electrical And Computer Science, Hoboken, NJ 07030

7. Authentication of Secret Information in Image Steganography, K Suresh Babu, K B Raja, Kiran Kumar K, Manjula Devi T H, Venugopal K R, L M Patnaik, Department of Computer Science and Engineering, University Visvesvaraya College of Engineering, Bangalore University,Bangalore 560 001

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