S Hemalatha

Bio: S Hemalatha is an academic researcher from Manipal Institute of Technology. The author has contributed to research in topics: Steganography & Steganography tools. The author has an hindex of 8, co-authored 17 publications receiving 208 citations. Previous affiliations of S Hemalatha include Manipal University.

A Secure and High Capacity Image Steganography Technique

Abstract: Steganography is the science of “invisible” communication. The purpose of Steganography is to maintain secret communication between two parties. The secret information can be concealed in content such as image, audio, or video. This paper provides a novel image steganography technique to hide multiple secret images and keys in color cover image using Integer W avelet Transform (IWT). There is no visual difference between the stego image and the cover image. The extracted secret images are also similar to the original secret images. Very good PSNR (Peak Signal to Noise Ratio) values are obtained for both stego and extracted secret images. The results are compared with the results of other techniques, where single image is hidden and it is found that the proposed technique is simple and gives better PSNR values than others

A Secure Color Image Steganography in Transform Domain

Abstract: Steganography is the art and science of covert communication. The secret information can be concealed in content such as image, audio, or video. This paper provides a novel image steganography technique to hide both image and key in color cover image using Discrete Wavelet Transform (DWT) and Integer Wavelet Transform (IWT). There is no visual difference between the stego image and the cover image. The extracted image is also similar to the secret image. This is proved by the high PSNR (Peak Signal to Noise Ratio), value for both stego and extracted secret image. The results are compared with the results of similar techniques and it is found that the proposed technique is simple and gives better PSNR values than others.

Comparison of secure and high capacity color image steganography techniques in RGB and YCbCr domains

Abstract: Steganography is one of the methods used for secret communication. Steganography attempts to hide the existence of the information. The object used to hide the secret information is called as cover object. Images are the most popular cover objects used for steganography. Different techniques have to be used for color image steganography and grey scale image steganography since they are stored in different ways. Color image are normally stored with 24 bit depth and grey scale images are stored with 8 bit depth. Color images can hold large amount of secret information since they have three color components. Different color spaces namely RGB (Red Green Blue), HSV (Hue, Saturation, Value), YUV, YIQ, YCbCr (Luminance, Chrominance) etc. are used to represent color images. Color image steganography can be done in any color space domain. In this paper color image steganography in RGB and YCbCr domain are compared. The secret information considered is grey scale image. Since RGB is the common method of representation, hiding secret information in this format is not secure.

A secure image steganography technique using Integer Wavelet Transform

Abstract: This paper proposes a secure image steganography technique to hide a secret image using the key. The secret image itself is not hidden, instead a key is generated and the key is hidden in the cover image. Using the key the secret image can be extracted. Integer Wavelet Transform (IWT) is used to hide the key. So it is very secure and robust because no one can realize the hidden information and it cannot be lost due to noise or any signal processing operations. Experimental results show very good Peak Signal to Noise Ratio (PSNR), which is a measure of security. In this technique the secret information is hidden in the middle bit-planes of the integer wavelet coefficients in high frequency sub-bands.

Secure and imperceptible digital image steganographic algorithm based on diamond encoding in DWT domain

Abstract: This paper presents a new efficient embedding algorithm in the wavelet domain of digital images based on the diamond encoding (DE) scheme. Current discrete wavelet transform (DWT) steganography adds an unacceptable distortion to the images and is considered as an ineffective in terms of security. Applying the DE scheme to the current DWT steganographic methods solves the problems of these methods, and reduces the distortion added to the images, and thus improves the embedding efficiency. The proposed algorithm first converts the secret image into a sequence of base-5 digits. After that, the cover image is transformed into the DWT domain and segmented into 2 × 1 coefficient pairs. The DE scheme is used then to change at most one coefficient of each coefficient pair to embed the base-5 digits. Experimental results depict that the proposed algorithm is more efficient in embedding compared to other methods in terms of embedding payload and image quality. Moreover, the proposed algorithm is attacked by well-known steganalysis software. Results are showing that the proposed algorithm is secure against the powerful universal steganalyzer “ensemble classifier” and the histogram attack. The results also reveal that the proposed algorithm is robust against different image processing attacks such as compression, added noise, and cropping attacks.

A Study of Various Steganographic Techniques Used for Information Hiding

Abstract: The art of information hiding has received much attention in the recent years as security of information has become a big concern in this internet era. As sharing of sensitive information via a common communication channel has become inevitable, Steganography – the art and science of hiding information has gained much attention. We are also surrounded by a world of secret communication, where people of all types are transmitting information as innocent as an encrypted credit card number to an online-store and as insidious as a terrorist plot to hijackers. Steganography derives from the Greek word steganos, meaning covered or secret, and graphy (writing or drawing) [1]. Steganography is a technology where modern data compression, information theory, spread spectrum, and cryptography technologies are brought together to satisfy the need for privacy on the Internet. This paper is an attempt to analyse the various techniques used in steganography and to identify areas in which this technique can be applied, so that the human race can be benefited at large.

A new transform domain steganography based on modified logistic chaotic map for color images

Abstract: The art and science of hiding information by embedding messages in various type of digital media is called steganography. This method performs by replacing bits of multimedia files (such as graphics, sounds and texts) with bits of secret message. The information that embeds in the cover media can be plain text, cipher text and even images. Steganography sometimes is used when encryption is not permitted or more commonly, steganography is supplement for encryption. By using steganography, if the encrypted file is deciphered, the encrypted file may still hide information. This paper is proposed a new transform domain steganography method based on integer wavelet transform (IWT) for digital images and also it used a chaotic map. This map is a modified logistic map which it increases the key length and security of proposed method. Experimental results shows that the proposed method has high capability in hiding information in any images which used as a cover media. Visual quality of image after embedding process is desirable due to Peak Signal-to-Noise Ratio (PSNR) measures. Also the NIST, DIEHARD and ENT tests suite show the proposed chaotic map randomness and sensitivity to smallest changes.

A modified DWT-based image steganography technique

Abstract: The main challenges of image steganography are imperceptibility of the cover image and no recoverability of the secret data. To deal with these challenges, a modified digital image steganography technique based on Discrete Wavelet Transform (DWT) is proposed. In proposed approach, two new concepts are being proposed to minimize the distortion in the cover image. The first one i.e. secret key computation concept is proposed to make it more robust and resistive towards steganalysis. The second one, known as blocking concept, is introduced to ensure least variation in the cover image. The proposed approach is tested over ten different cover images and two secret images. Its performance is compared with the six well-known steganography techniques. The experimental results reveal that the proposed approach performs better than the existing techniques in terms of imperceptibility, security and quality measures. The six image processing attacks are also applied on the stego-image to test the robustness of the proposed approach. The effects of compression, rotation, and application of different wavelets have also been investigated on the proposed approach. The results demonstrate the robustness of the proposed approach under different image processing attacks. Both stego-image and extracted secret images possess better visual quality.

A Secure And High Capacity Image Steganography Technique

Abstract: Steganography is the science of invisible communication. The purpose of Steganography is to maintain secret communication between two parties. The secret information can be concealed in content such as image, audio, or video. This paper provides a novel image steganography technique to hide multiple secret images and keys in color cover image using Integer Wavelet Transform (IWT). There is no visual difference between the stego image and the cover image. The extracted secret images are also similar to the original secret images. Very good PSNR (Peak Signal to Noise Ratio) values are obtained for both stego and extracted secret images. The results are compared with the results of other techniques, where single image is hidden and it is found that the proposed technique is simple and gives better PSNR values than others.