International Journal of Engineering, Management & Sciences (IJEMS) ISSN-2348 –3733, Volume-2, Issue-6, June 2015
A Secure Steganography Technique using Discrete Wavelet Transformation Priyanka Mudgal, Neeraj Mangalani Abstract— Information security is the basic requirement of today digital communication. Everything is going digital, so the protection of information is much more important. The information security can be classified in to Steganography, Watermarking and Cryptography. steganography is the art and science of hiding secret information into digital media, so that no one can identified the presence inside the media. There are different types of carriers (ie. Image , video etc) for cover media. Steganalysis is type of attack against the steganography technique. To make security in communication system, new steganography method based on Discrete wavelet Transform is proposed. The proposed method hides secret message bits inside the intensity matrix of secret image. Then the Inverse Discrete Wavelet Transformation (IDWT) is applied to obtain the stego image. The performance of proposed design is investigated by comparing cover and stego image in terms of Peak Signal to Noise Ratio (PSNR), Mean Square Error (MSE). Index Terms— Information hiding, Cryptography, Steganography, Watermarking, PSNR, MSE.
I. INTRODUCTION The term steganography is indoors from Greek word which basic meaning is “Covered Writing”. Embedder can select any digital cover media (like: image, audio file) that grades in most secure stego file. Today, computers and internet have become the most powerful source of communication among the people in the different parts of the world. Long distances between the people are no longer an obstruction to exchange data between them. However, the safety and security of the exchanged data is of great fear, particularly in the case if it is confidential. There is need to develop good steganography algorithm, because steganography is more power full technique for secure communication. Future is always invisible in steganography that provide more resistance, steganalysis[1 ][2 ][3 ]. II. WAVELET TRANSFORM IN INFORMATION SECURITY Wavelet Transform is the related field in signal and image processing. Which provides the grater advantage in term of robustness and capacity for hiding the data or other types of information.The work described in this paper implements steganography in the Wavelet domain. In Wavelet transform, the original signal, which may be one dimensional, two -Dimensional, three dimensional, is transformed using
Manuscript received June 10, 2015. Priyanka Mudgal, M.Tech(scholar), Jagannath Chaksu,Jaipur. Neeraj Mangalani, Assistant Professor, Jagannath Chaksu,Jaipur
predefined wavelets. The wavelets are orthogonal, or biorthogonal [4][5][6]. A signal can be decomposed into two parts, high frequencies and low frequencies through a wavelet transformation. The low frequencies part is decomposed again into two parts of higher and lower frequencies. The number of decompositions in this process is usually determined by application and length of the original signal. The data obtained from the above decomposition are called the DWT coefficients. Moreover, these coefficients can be used to reconstruct the original signal. This reconstruction is known as the inverse DWT (IDWT)[4].fig 1 shows a 2-D DWT.
Fig1 . 2-Dimensnal Wavelet Transformation for an image file III. IMAGE PIXELS AND INTENSITY The original image and its 8 times magnified view with pixel grid is shown in Figures 2 (a) and 2 (b) respectively.
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