Manashee Kalita

Abstract: This paper presents a novel steganographic method based on Least Significant Bit (LSB) substitution and 8-neighboring Pixel Value Differencing (8nPVD) for gray scale image in order to improve the embedding capacity with an imperceptible stego image. The proposed method partitions the cover image into some 3×3 non-overlapping pixel blocks in row major order. k-bits of the secret bit stream are embedded in the center pixel of the block using modified LSB substitution. The difference between the center pixel and 8-neighboring pixels are employed to find out the number of bits that can be embedded in the difference value. The method divides the gray levels [0-255] into five different continuous ranges. The number of bits to be embedded is calculated from the range table. The experimental results show that the proposed method has a higher embedding capacity and Peak Signal to Noise Ratio (PSNR) value of the stego image against the cover image. This work also presents a comparison of the embedding capacity and PSNR value of the proposed method with the existing scheme [5], [7].

Abstract: Steganography is a data hiding technique, which is used for securing data. Both spatial and transform domains are used to implement a steganography method. In this paper, a novel transform domain method is proposed to provide a better data hiding method. The method uses a multi-resolution transform function, integer wavelet transform (IWT) that decomposes an image into four subbands: low-low, low-high, high-low and high-high subband. The proposed method utilizes only the three subbands keeping the low-low subband untouched which helps to improve the quality of the stego image. The method applies a coefficient value differencing approach to determine the number of secret bits to be embedded in the coefficients. The method shows a good performance in terms of embedding capacity, imperceptibility and robustness. A number of metrics are computed to show the quality of the stego image. It can also withstand RS steganalysis, Chi-squared test and Subtractive Pixel Adjacency Matrix steganalysis successfully. The deformation of the histogram and Pixel Difference Histogram for different embedding percentages are also demonstrated, which show a significant similarity with the original cover image. The proposed method shows an achievement of 2.3bpp embedding capacity with a good quality of stego image.

Abstract: Transmitting data from sender to authorized receiver through a public media (insecure media) with full security is a challenging task. From the ancient time, different methods and techniques have been adopted to gain secure transmission of information. With the development of new technologies, the techniques used for securing information have also changed. The three main technology used for securing digital content are watermarking, steganography and cryptography. Watermarking and steganography can be considered under the same roof, i.e. data hiding techniques. In the last decade, steganography has drawn more attention of researchers. This paper presents a comparative study of steganography algorithms both in the spatial and transform domain.

Abstract: Steganography is a data-concealing technique that provides a covert communication. This paper proposes a spatial domain color steganography method that uses a neighboring pixel-pair differencing co...

Abstract: Steganography deals with embedding secret data within inoffensive looking objects called “Cover Objects.” To accomplish this, intensive computations are required to be performed. Modern day steganography can be implemented using both software and hardware for the purpose of obscurity based security or Kerckhoffs's principle based Shannon's maxim. The algorithm used in both the implementations may be in spatial or transform domain. Moreover, hardware implementations may be done via a lot of variants among which FPGA (Field Gate Programmable Array) based implementations are most user-friendly and easy to implement and reconfigure. Hardware implementation speeds up the embedding process where as transform domain increases robustness. But the complexity of transform domain is huge compared to the spatial domain. So the simple and fast FPGA-based spatial domain real time hardware implementation of steganography becomes an important field to explore. This paper gives an overview of the hardware platforms and discusses several works done in implementing steganographic algorithms in hardware mainly in the FPGA-based spatial domain.

Abstract: Storing and communicating secret and/or private information has become part of our daily life whether it is for our employment or personal well-being. Therefore, secure storage and transmission of the secret information have received the undivided attention of many researchers. The techniques for hiding confidential data in inconspicuous digital media such as video, audio, and image are collectively termed as Steganography. Among various media types used, the popularity and availability of digital images are high and in this research work and hence, our focus is on implementing digital image steganography. The main challenge in designing a steganographic system is to maintain a fair trade-off between robustness, security, imperceptibility and higher bit embedding rate. This research article provides a thorough review of existing types of image steganography and the recent contributions in each category in multiple modalities. The article also provides a complete overview of image steganography including general operation, requirements, different aspects, different types and their performance evaluations. Different performance analysis measures for evaluating steganographic system are also discussed here. Moreover, we also discuss the strategy to select different cover media for different applications and a few state-of-the-art steganalysis systems.

Abstract: The protection of confidential information transmitted over the Internet and restricting access to specific classified data have become a major security and privacy issue. To conceal the existence of such data, digital image steganography is employed hiding the secret in questions within a cover image, arriving at a new image that is virtually indistinguishable from the original. Thus, concealed data within the cover image is prevented from being detected via unauthorized access. In light of the above, certain aspects, such as the capacity of the cover image and the imperceptibility, need to be analyzed and addressed as they constitute the crucial assessment parameters for the performance of the steganography algorithms. In this paper, we compare the steganography algorithms of least significant bit and discrete wavelet transform in terms of efficiency and capacity of concealing multiple images within a single cover image. We cover the mechanism of the embedding and extraction algorithms for multiple numbers of images to come up with knowledgeable remarks. Furthermore, performance of these stego-algorithms has been evaluated with regard to the capacity of the cover image, imperceptibility of the data, and security.

Abstract: This paper presents a novel steganographic method based on Least Significant Bit (LSB) substitution and 8-neighboring Pixel Value Differencing (8nPVD) for gray scale image in order to improve the embedding capacity with an imperceptible stego image. The proposed method partitions the cover image into some 3×3 non-overlapping pixel blocks in row major order. k-bits of the secret bit stream are embedded in the center pixel of the block using modified LSB substitution. The difference between the center pixel and 8-neighboring pixels are employed to find out the number of bits that can be embedded in the difference value. The method divides the gray levels [0-255] into five different continuous ranges. The number of bits to be embedded is calculated from the range table. The experimental results show that the proposed method has a higher embedding capacity and Peak Signal to Noise Ratio (PSNR) value of the stego image against the cover image. This work also presents a comparison of the embedding capacity and PSNR value of the proposed method with the existing scheme [5], [7].

Abstract: The amount of data exchanged via the Internet is increasing nowadays. Hence, data security is termed as a serious issue while communication of data is processed over the Internet. Everyone needs th...

Abstract: The development of the Internet provides the ability to transfer large amounts of data quickly and easily. However, sensitive data is easily intercepted by hackers on the Internet. Image steganography ensures the secure transmission of information. In order to improve the capacity of hidden secret data and provide imperceptible hidden image quality, this paper proposes a hybrid steganography method based on least significant bit (LSB) replacement and Hamming code (HLAH). Information security is also increased by using two different steganographic methods. Since the sharp areas of the image can tolerate more changes than the smooth areas, more secret messages are embedded in the edge regions of the image and a small amount of information are embedded in the smooth regions. Finally, the performance of the proposed HLAH method is evaluated by measuring payload capacity, mean square error (MSE), peak signal-to-noise ratio (PSNR), and histogram analysis. The experimental results show that the proposed HLAH method not only has greater embedding capacity than other existing methods, but also ensures higher image quality.