40 research outputs found

    JPEG steganography: A performance evaluation of quantization tables

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    The two most important aspects of any image based steganographic system are the imperceptibility and the capacity of the stego image. This paper evaluates the performance and efficiency of using optimized quantization tables instead of default JPEG tables within JPEG steganography. We found that using optimized tables significantly improves the quality of stego-images. Moreover, we used this optimization strategy to generate a 16x16 quantization table to be used instead of that suggested. The quality of stego-images was greatly improved when these optimized tables were used. This led us to suggest a new hybrid steganographic method in order to increase the embedding capacity. This new method is based on both and Jpeg-Jsteg methods. In this method, for each 16x16 quantized DCT block, the least two significant bits (2-LSBs) of each middle frequency coefficient are modified to embed two secret bits. Additionally, the Jpeg-Jsteg embedding technique is used for the low frequency DCT coefficients without modifying the DC coefficient. Our experimental results show that the proposed approach can provide a higher information-hiding capacity than the other methods tested. Furthermore, the quality of the produced stego-images is better than that of other methods which use the default tables

    An Effective Data Embedding Technique Based on APPM in Transform Domain

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    This paper proposes an efficient data embedding technique based on adaptive pixel pair matching in transform domain. The basic principle of a Pixel Pair Matching (PPM) based data embedding technique is to use the values of a pixel pair as a reference coordinate and search a coordinate in the neighborhood set of that pixel pair according to given message digit. In order to conceal secret data the pixel pair is then replaced by the searched coordinate. In transform domain data embedding techniques, the image pixels are converted into transform domain by using a particular transform and then the secret data is embedded by using an efficient data embedding algorithm. In this paper the Haar transform is used. The proposed method not only offers lower embedding distortion but also more robust against various noise attacks. The experimental results shows that this method performs better when compared to the spatial domain technique

    LARGE DATA EMBEDDING; PROBLEM & SOLUTION

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    The objective of the study was to propose a high capacity data embedding system from DCT domain. The default quantization table is used for fixed mask projection quantization steps. Accordingly, DCT coefficient of the host image from low to higher frequency bands and embed bits from band to band with specially designed base vectors called Hadamard vectors. The embedding scheme procedure is described step wise. The proposed system can be used for data embedding and can be associated with another encryption method to make it safer. The proposed system is reported to be highly robust and secur

    A Spatial Domain Image Steganography Technique Based on Plane Bit Substitution Method

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    Steganography is the art and science of hiding information by embedding data into cover media. In this paper we propose a new method of information hiding in digital image in spatial domain. In this method we use Plane Bit Substitution Method (PBSM) technique in which message bits are embedded into the pixel value(s) of an image. We first, proposed a Steganography transformation machine (STM) for solving Binary operation for manipulation of original image with help to least significant bit (LSB) operator based matching. Second, we use pixel encryption and decryption techniques under theoretical and experimental evolution. Our experimental, techniques are sufficient to discriminate analysis of stego and cover image as each pixel based PBSM, and operand with LSB

    Data hiding techniques in steganography using fibonacci sequence and knight tour algorithm

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    The foremost priority in the information and communication technology era, is achieving an efficient and accurate steganography system for hiding information. The developed system of hiding the secret message must capable of not giving any clue to the adversaries about the hidden data. In this regard, enhancing the security and capacity by maintaining the Peak Signal-to-Noise Ratio (PSNR) of the steganography system is the main issue to be addressed. This study proposed an improved for embedding secret message into an image. This newly developed method is demonstrated to increase the security and capacity to resolve the existing problems. A binary text image is used to represent the secret message instead of normal text. Three stages implementations are used to select the pixel before random embedding to select block of (64 × 64) pixels, follows by the Knight Tour algorithm to select sub-block of (8 × 8) pixels, and finally by the random pixels selection. For secret embedding, Fibonacci sequence is implemented to decomposition pixel from 8 bitplane to 12 bitplane. The proposed method is distributed over the entire image to maintain high level of security against any kind of attack. Gray images from the standard dataset (USC-SIPI) including Lena, Peppers, Baboon, and Cameraman are implemented for benchmarking. The results show good PSNR value with high capacity and these findings verified the worthiness of the proposed method. High complexities of pixels distribution and replacement of bits will ensure better security and robust imperceptibility compared to the existing systems in the literature

    Scaling Factor Threshold Estimator in Different Color Models Using a Discrete Wavelet Transform for Steganographic Algorithm

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    Two of the main problems with steganographic algorithms are insertion capability and minimization of distortion in the digital files where the hidden information is the information is inserted to hiding Digital filters are generally used as noise detectors, and they also suppress information outside the original information contained in the file. There are different types of filtering, one in the spatial domain and the other in the frequency domain or sometimes a combination of both domains to propose adaptive filters. One of the filters with greater application is the discrete wavelet transform (DWT) because it is easy to implement and has low computational complexity. The DWT computationally implemented in an image can be represented as a quadrature mirror filter, separating the frequency components: so high-high, high-low, low-high and low-low levels obtain different resolutions

    Pokročilé metody detekce steganografického obsahu

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    Steganography can be used for illegal activities. It is essential to be prepared. To detect steganography images, we have a counter-technique known as steganalysis. There are different steganalysis types, depending on if the original artifact (cover work) is known or not, or we know which algorithm was used for embedding. In terms of practical use, the most important are “blind steganalysis” methods that can be applied to image files because we do not have the original cover work for comparison. This philosophiæ doctor thesis describes the methodology to the issues of image steganalysis.In this work, it is crucial to understand the behavior of the targeted steganography algorithm. Then we can use it is weaknesses to increase the detection capability and success of categorization. We are primarily focusing on breaking the steganography algorithm OutGuess2.0. and secondary on breaking the F5 algorithm. We are analyzing the detector's ability, which utilizes a calibration process, blockiness calculation, and shallow neural network, to detect the presence of steganography message in the suspected image. The new approach and results are discussed in this Ph.D. thesis.Steganografie může být využita k nelegálním aktivitám. Proto je velmi důležité být připraven. K detekci steganografického obrázku máme k dispozici techniku známou jako stegoanalýza. Existují různé typy stegoanalýzy v závislosti na tom, zda je znám originální nosič nebo zdali víme, jaký byl použit algoritmus pro vložení tajné zprávy. Z hlediska praktického použití jsou nejdůležitější metody "slepé stagoanalýzy", které zle aplikovat na obrazové soubory a jelikož nemáme originální nosič pro srovnání. Tato doktorská práce popisuje metodologii obrazové stegoanalýzy. V této práci je důležité porozumět chování cíleného steganografického algoritmu. Pak můžeme využít jeho slabiny ke zvýšení detekční schopnosti a úspěšnosti kategorizace. Primárně se zaměřujeme na prolomení steganografického algoritmu OutGuess2.0 a sekundárně na algoritmus F5. Analyzujeme schopnost detektoru, který využívá proces kalibrace, výpočtu shlukování a mělkou neuronovou síť k detekci přítomnosti steganografické zprávy na podezřelém snímku. Nový přístup a výsledky jsou sepsány v této doktorské práci.460 - Katedra informatikyvyhově

    Bit inverting map method for improved steganography scheme

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    Achieving an efficient and accurate steganography scheme for hiding information is the foremost priority in the information and communication technology era. The developed scheme of hiding the secret message must capable of not giving any clue to the adversaries about the hidden data. In this regard, enhancing the security and capacity by maintaining the Peak Signal-to-Noise Ratio (PSNR) of the steganography scheme is the main issue to be addressed. This study proposes an improved Bit Inverting Map (BIM) method and a new scheme for embedding secret message into an image. This newly developed scheme is demonstrated to increase the security and capacity to resolve the existing problems. A binary text image is used to represent the secret message instead of normal text. Three stages implementations are used to select pixels before random embedding to select block of (64 64) pixels, followed by the Knight Tour algorithm to select sub-block of (8 8) pixels, and finally by the random pixels selection. The proposed BIM is distributed over the entire image to maintain high level of security against any kind of attack. One-bit indicator is used to decide if the secret bits are inserted directly or inversely, which enhanced the complexity of embedding process. Color and gray images from the standard dataset (USC-SIPI) including Lena, Peppers, Baboon, and Cameraman are implemented for benchmarking. Self-captured images are used to test the efficacy of the proposed BIM method. The results show good PSNR values of 72.9 and these findings verified the worthiness of the proposed BIM method. High complexities of pixels distribution and replacement of bits will ensure better security and robust imperceptibility compared to the existing scheme in the literature

    Embedding in Two Least Significant Bits with Wet Paper Coding

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    In this paper, we present three embedding schemes for extensions of least significant bit overwriting to both of the two lowest bit planes in digital images. Our approaches are inspired by the work of Fridrich et al. [8] who proposed wet paper coding as an efficient method for steganographic schemes. Our new works generalize it to the embedding in two least significant bits, that is to say, combine two novel extensions of least significant bits embedding and the double-layered embedding developed in [16] with wet paper coding, respectively. The proposed schemes improve steganographic security and are less vulnerable to steganalytic attacks compared with original schemes with shared selection channels between the sender and the recipient
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