DWT based approach for steganography using biometrics

A DWT based Approach for Steganography Using Biometrics

Guided by:V. Sree lakshmi

(Snr Assistant Professor)

Submitted By :

N.S.Srimadhur(10B81A04A0)

D.Sri Hari Priya(10B81A0499) D.Vishwa Teja(10B81A04D8)

What is Steganography?

Steganography is the art of hiding the existence of data in another transmission medium to achieve secret communication. It does not replace cryptography but rather boosts the security using its obscurity features.

The word steganography is of Greek origin and means "concealed writing" from the Greek words steganos meaning "covered or protected", and graphein meaning "writing".

“Steganography means hiding one piece of data within another”.

Steganography method used in this paper is based on biometrics.

Here secret data is embedded within skin region of image that will provide an excellent secure location for data hiding. For this skin tone detection is performed using HSV (Hue,

Saturation and Value) color space. Additionally secret data embedding is performed using

frequency domain approach - DWT (Discrete Wavelet Transform).

Abstract :

Basic Steganography Model

Carrier or Cover File - A Original message or a file in

which hidden information will be stored inside of it .

Stego-Medium - The medium in which the information is hidden.

Embedded or Payload - The information which is to be hidden or concealed.

Steganalysis - The process of detecting hidden information inside a file.

Steganography Terms

Carrier Image Image to be embedded

Skin Color Tone Detection

Proposed method introduces a new method of embedding secret data within skin as it is not that much sensitive to HVS (Human Visual System).

This takes advantage of Biometrics features such as skin tone, instead of embedding data anywhere in image, data will be embedded in selected regions.

Skin segmentation

Carrier image after skin detection

Types of morphological operations:

Dilation

Erosion

Opening

Closing

Morphological operations

The structuring element taken here is disk structure of radius r= 3

Neighborhood:

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

Structuring element

It is typically applied to binary images, but there are versions that work on gray scale images.

The erosion of A by the structuring element B is defined by:

The erosion of A by B is the set of all displacements, z, such that and A if atleast 1 element coincides with background value then that value sets to background pixel.

Erosion

Common Names: Erode, Shrink, Reduce

It is typically applied to binary images, but there are versions that work on gray scale images.

The dilation of A by the structuring element B is defined by:

The dilation of A by B is the set of all displacements, z, such that and A overlap by at least 1 element Thus, Set B is referred to as the structuring element in dilation.

Dilation

Common Names: Dilate, Grow, Expand

Opening:smooth the contour of an object, break narrow isthmuses, and

eliminate thin protrusions.The opening A by B is the erosion of A by B, followed by a

dilation of the result by B

Closing:smooth sections of contours but it generally fuses narrow

breaks and long thing gulfs, eliminates small holes, and fills gaps in the contour.

Opening and Closing

Output of Erosion

Output of Closing

Applying dilution 2 times

Again applying closing operation

Applying Filling Operation

DWT splits component into numerous frequency bands called sub bands known as

LL – Horizontally and vertically low pass LH – Horizontally low pass and vertically high pass HL - Horizontally high pass and vertically low pass HH - Horizontally and vertically high pass. we hide secret message in other three parts without making

any alteration in LL sub band. DWT used in this work is Haar-DWT, the simplest DWT.

Transformation of cover image in to frequency domain:

Block diagram for embedding process:

Cropped image

Perform DWT

Embedding in B-plane

Secret logo

Perform IDWT

Cropped stego image

Merging with

original image

Stego image

Face segmented image

Stego image

Block diagram for extraction process

Load stego image

Perform skin

detection

Crop the

image

Perform DWT

retrievalSecret data

Retrived image

The phrase peak signal-to-noise ratio, often abbreviated PSNR, is an engineering term for the ratio between the maximum possible power of a signal and the power of corrupting noise that affects the fidelity of its representation.

Peak signal-to-noise ratio

The health care, and especially medical imaging systems, may very much benefit from information hiding techniques.It is used for DIGITAL SIGNATURE AUTHENTICATION to prevent malicious tampering of private and confidential documents. These documents include company memos, Emails and letters.It can also be implemented for identity proofs as personal details can be embedded in face.

Applications

In this paper biometric steganography is presented that uses skin region of images in DWT domain for embedding secret data. By embedding data in only certain region (here skin region) and not in whole image security is enhanced. Also image cropping concept introduced, maintains security at respectable level since no one can extract message without having value of cropped region.

Conclusion

Any queries ?

THANK YOU