cryptography plus steganography

STEGANOGRAPHY

STEGANOGRAPHY

By -Deepanshi Arora M.tech(2nd sem )

INTRODUCTIONInternet being an integral part of todays world, is an unsafe medium for transfer of secret information.

A genuine approach to this problem is encryption. However it marks a message as containing imp info. Suspecting security.

A significant approach STEGANOGRAPHY overcomes this issue.

CRYPTO + STEGNO

Cryptography scrambles a message so it cannot be understood

The Steganography hides the message so it cannot be seen.

Even though both methods provide security, a study is made to combine both cryptography and Steganography methods into one system for better confidentiality and security.

Steganography vs. CryptographyCRYPTOGRAPHY (i) Message is not hidden. (ii) Enemy can intercept the message. (iii) Enemy can decrypt the message.

STEGANOGRAPHY (i) Message is hidden.(ii) Enemy can discover the medium.

The steganography approaches can be divided into three types

Pure Steganography: This technique simply uses the steganography approach only without combining other methods. Secret Key steganography: This uses the combination of the secret key cryptography technique and the steganography approach.. Public Key Steganography: To combine the public key cryptography approach and the steganography approach..

PROJECT SCOPE This Project is for hiding information in any image file. The scope of the project is implementation of steganography tools for hiding information.

This project proposes a secure communication system. It employs cryptographic algorithm together with steganography. The jointing of these techniques provides a robust and strong communication system that able to withstand against attackers.

LITERATURE SURVEYIMAGE BASED STEGANOGRAPHY AND CRYPTOGRAPHY by Domenico Bloisi and Luca Iocchi,2013

In this paper they described a method for integrating together cryptography and steganography through image processing using images as cover objects for steganography and as keys for cryptography.

They showed that it is an effective system (making a comparison with the well known F5 algorithm) and is also a theoretically unbreakable cryptographic one.

LITERATURE SURVEY CONTD.Secure Data Hiding Algorithm Using Encrypted Secret message by Harshitha K M, Dr. P. A. Vijaya International Journal of Scientific and Research Publications, Volume 2, Issue 6, June 2012 1 ISSN 2250-3153, www.ijsrp.org

The hidden message is encrypted using a simple encryption algorithm

N-bit LSB substitution technique is used as embedding and extraction method .

The MAIN OBJECTIVES are:

To embed the maximum amount of data (secret message) in cover image.

To embed maximum data in cover image with minimum changes in the original cover image.

If intruder somehow makes some changes in stego image, still we should be able to retrieve the secret message.

METHODOLOGYTwo Tab Options----Encrypt & Decrypt..

ENCRYPTION--The secrete information is hiding in with any type of image file.

DECRYPTION -- It is getting the secret information from image file.

SOME DEFINITIONS

Cover medium: This is the medium in which we want to hide data

Embedded message: This is the hidden message we want to put in the cover.

Stego-key: This is represented by some secret information, which is needed in order to extract the embedded message from the stegomedium

Stego-medium: This is the final piece of information that the casual observer can see.

We can define this simple formula:

Cover-medium + Embedded-message = Stego-message

BLOCK DIAGRAM

ALGORITHM- TRANSMITTER SIDEStep 1 - Reading a text file and converting it to binaryStep 2 - Key generationStep 3 - Converting key to binaryStep 4 - Reading the image and converting the pixel values to binaryStep 6 Applying STEGO Tech. (LSB substitution)Step 7 - Getting stego image.

ALGORITHM- RECIEVER SIDEStep1 : Reading the Stego imageStep 2 : Extracting the data from imageStep 3 : DecryptionStep 4 : Converting data to ASCII form and writing to file

CRYPTOGRAPHY TECHNIQUESThere are some standards methods which are used with cryptography such as : Secret key Public key : DIFFIE - HELLMAN Digital signature Hash function

Image Steganography Techniques

Substitution Technique -LSBTransform Domain Technique-DCTSpread Spectrum Technique

Statistical Technique

Distortion Technique

LSB-Least Significant BitLeast significant bit (LSB) insertion is a common and simple approach for embedding information in a cover file.

Unfortunately, it is vulnerable to even a slight image manipulation.

HIDING METHOD

EMBEDDING THE INFORMATION

EMBEDDING a IN A PIXEL

DCT- Discrete Cosine TransformIt transforms a cover image from an image representation into a frequency representation by grouping the pixels into non-overlapping blocks of 8 8 pixels and by transforming each of the pixel blocks into 64 DCT coefficients. The DCT coefficients of the transformed cover image will be rounded off, and then modified according to the secret data

Images are widely used to store and transmit the information through internet . It has capacity of holding the information to 50% of original size

In military operations.

Usage in modern communication.

Used in digital watermarking.

APPLICATIONS

CONCLUSION Steganography is a fascinating and effective method of hiding data that has been used throughout history.

It is used for data hiding, watermarking or more secure central storage method for such things as passwords, or key processes.

Regardless, the technology is easy to use and difficult to detect.

REFERENCESNeha Sharma, J.S. Bhatia and Dr. Neena Gupta, An Encrypto-Stego Technique Based secure data Transmission System, PEC, Chandigarh. Saleh Saraireh, Department of Communications and Electronic Engineering, Philadelphia University,Amman, A SECURE DATA COMMUNICATION SYSTEM USING CRYPTOGRAPHY AND STEGANOGRAPHY International Journal of Computer Networks & Communications (IJCNC) Vol.5, No.3, May 2013

I. Venkata Sai Manoj, Cryptography and Steganography, International Journal of Computer Applications (0975 8887), Volume 1 No.12

B B Zaidan, A.A Zaidan, A.K. Al-Frajat and H.A. Jalab, On the Differences between Hiding Information and Cryptography Techniques: An Overview, Journal of Applied Sciences 10(15): 1650-1655, 2010

REFERENCES CONTD.Kallam Ravindra Babu, Dr. S.Udaya Kumar, Dr. A.Vinaya Babu, A Survey on Cryptography and Steganography Methods for Information Security, Internaltional Journal of Computer Applications(0975-8887), Volume 12 No. 2, November 2010. Dipti Kapoor Sarmah, Neha bajpai, Proposed System for Data Hhiding Using Cryptography and Steganography, International Journal of Computer Applications (0975 8887), Volume 8 No. 9, October 2010. Eiji Kawaguchi and Richard O. Eason, Principle and applications of BPCS-Steganography, Kyushu Institute of Technology, Kitakyushu, Japan, University of Maine, Orono, Maine 04469-5708. Sashikala Channalli and Ajay Jadhav, Steganography An Art of Hiding Data, International Journal on Computer Science and Engineering Vol.1(3), 2009, 137-141. A.Joseph Raphael,Dr.V Sundaram, Int. J. Comp. Tech. Appl., Vol 2 (3), 626-630 630