Image Steganography

By: Ankit Goyal (101303022) Ankit Gupta (101303023) Nilansh Arora (101483018) Tanishq Monga (101483029)

Steganography

What is Steganography?

Steganography is the art and science of writing hidden messages in such a way that no one apart from the intended recipient knows of the existence of the message.

This can be achieved by concealing the existence of information within seemingly harmless carriers or covers (text, image, video, audio, etc.)onot encryption•original image/file is intact

onot fingerprinting•fingerprinting leaves separate file describing contents

Image SteganographyImage Steganography is the technique of hiding

the data within the image in such a way that prevents the unintended user from the detection of the hidden messages or data.

Applications of Image SteganographySecure Private Files and Documents.Hide Passwords and Encryption Keys.Transport Highly Private Documents between

International Governments.Transmit message/data without revealing the

existence of available message.

Algorithm used

Least Significant Bit Substitution results in a very minor distortion of the image which is very much negligible for the human eyes.

Original Image Stego Image

Algorithm used(..contd)Algorithm to embed the message:

•Read the cover image and text message which is to be hidden in the cover image.•Convert the color image into grey image.•Convert text message into binary.•Calculate LSB of each pixel of cover image.•Replace LSB of cover image with each bit of secret message one by

one.•Write stego image.

Algorithm to extract message

•Read the stego image.

•Calculate the LSB of each pixel of stego image.

•Extract the bits and covert each 8 bit in to character.

ExampleWe can use images to hide things if we replace the last bit of every color’s byte with a bit from the message. Message A-01000001

Image with 3 pixels Pixel 1: 11111000 11001001 00000011 Pixel 2: 11111000 11001001 00000011 Pixel 3: 11111000 11001001 00000011

Example(..cont)Now we hide our message in the image. Message: 01000001

Pixel 1: 11111000 11001001 00000010 Pixel 2: 11111000 11001000 00000010 Pixel 3: 11111000 11001001 00000011

New image:

Outcomes of the project

User-Interface of the application

(..contd)

Encryption window of the application

(..contd)

Decryption window of the application

ConclusionsPros•Secrecy and confusion•Variety of combinations•Can be combined with cryptography

Cons•Not suitable for massive transmissions•Requires more effort than regular cryptography•Weak against transformation•Specific solutions for specific problems

AchievementsGot successful in hiding high priority data in an image.

Learnt the concepts of LSB substitution algorithm.

Made an application with user interface to encrypt/decrypt the data in an image.

References• Information Hiding - A Survey Fabien A. P. Petitcolas, Ross J. Anderson and Markus G. Kuhn Proceedings of the IEEE, special issue on protection of multimedia content, 87(7):1062-1078, July 1999.

•Anil k Jain, “Fundamentals of digital image processing", University of california-davis,prentice hall.

•Proceeding of the 2006 International conference on “Intelligent information hiding and multimedia signal processing 2006 IEEE.

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