Showing papers on "Steganography published in 2007"

Digital Watermarking and Steganography

Abstract: Digital audio, video, images, and documents are flying through cyberspace to their respective owners. Unfortunately, along the way, individuals may choose to intervene and take this content for themselves. Digital watermarking and steganography technology greatly reduces the instances of this by limiting or eliminating the ability of third parties to decipher the content that he has taken. The many techiniques of digital watermarking (embedding a code) and steganography (hiding information) continue to evolve as applications that necessitate them do the same. The authors of this second edition provide an update on the framework for applying these techniques that they provided researchers and professionals in the first well-received edition. Steganography and steganalysis (the art of detecting hidden information) have been added to a robust treatment of digital watermarking, as many in each field research and deal with the other. New material includes watermarking with side information, QIM, and dirty-paper codes. The revision and inclusion of new material by these influential authors has created a must-own book for anyone in this profession. *This new edition now contains essential information on steganalysis and steganography *New concepts and new applications including QIM introduced *Digital watermark embedding is given a complete update with new processes and applications

Merging Markov and DCT Features for Multi-Class JPEG Steganalysis

Abstract: Blind steganalysis based on classifying feature vectors derived from images is becoming increasingly more powerful. For steganalysis of JPEG images, features derived directly in the embedding domain from DCT coefficients appear to achieve the best performance (e.g., the DCT features10 and Markov features21). The goal of this paper is to construct a new multi-class JPEG steganalyzer with markedly improved performance. We do so first by extending the 23 DCT feature set,10 then applying calibration to the Markov features described in21 and reducing their dimension. The resulting feature sets are merged, producing a 274-dimensional feature vector. The new feature set is then used to construct a Support Vector Machine multi-classifier capable of assigning stego images to six popular steganographic algorithms-F5,22 OutGuess,18 Model Based Steganography without ,19 and with20 deblocking, JP Hide&Seek,1 and Steghide.14 Comparing to our previous work on multi-classification,11, 12 the new feature set provides significantly more reliable results.

Statistically undetectable jpeg steganography: dead ends challenges, and opportunities

Abstract: The goal of this paper is to determine the steganographic capacity of JPEG images (the largest payload that can be undetectably embedded) with respect to current best steganalytic methods. Additionally, by testing selected steganographic algorithms we evaluate the influence of specific design elements and principles, such as the choice of the JPEG compressor, matrix embedding, adaptive content-dependent selection channels, and minimal distortion steganography using side information at the sender. From our experiments, we conclude that the average steganographic capacity of grayscale JPEG images with quality factor 70 is approximately 0.05 bits per non-zero AC DCT coefficient.

Digital Watermarking and Steganography: Fundamentals and Techniques

Abstract: In addition to providing students, researchers, and other professionals with mechanical information regarding digital watermarking and steganography, this work also provides them with the framework needed to develop extensive advanced algorithms. It shows how robust high-capacity watermarking techniques can be successfully used to enlarge the hiding capacity while maintaining the robustness of the watermark. Several robust algorithms are presented to illustrate the framework and provide assistance in understanding and implementing fundamental principles. Alternatives to traditional strategies are presented. The principles taught are illustrated with plentiful graphs and examples in order to simplify the problems and make highly complicated theories readily understandable.

YASS: yet another steganographic scheme that resists blind steganalysis

Abstract: A new, simple, approach for active steganography is proposed in this paper that can successfully resist recent blind steganalysis methods, in addition to surviving distortion constrained attacks. We present Yet Another Steganographic Scheme (YASS), a method based on embedding data in randomized locations so as to disable the self-calibration process (such as, by cropping a few pixel rows and/or columns to estimate the cover image features) popularly used by blind steganalysis schemes. The errors induced in the embedded data due to the fact that the stego signal must be advertised in a specific format such as JPEG, are dealt with by the use of erasure and error correcting codes. For the presented JPEG steganograhic scheme, it is shown that the detection rates of recent blind steganalysis schemes are close to random guessing, thus confirming the practical applicability of the proposed technique. We also note that the presented steganography framework, of hiding in randomized locations and using a coding framework to deal with errors, is quite simple yet very generalizable.

Optimized Feature Extraction for Learning-Based Image Steganalysis

Abstract: The purpose of image steganalysis is to detect the presence of hidden messages in cover photographic images. Supervised learning is an effective and universal approach to cope with the twin difficulties of unknown image statistics and unknown steganographic codes. A crucial part of the learning process is the selection of low-dimensional informative features. We investigate this problem from three angles and propose a three-level optimization of the classifier. First, we select a subband image representation that provides better discrimination ability than a conventional wavelet transform. Second, we analyze two types of features-empirical moments of probability density functions (PDFs) and empirical moments of characteristic functions of the PDFs-and compare their merits. Third, we address the problem of feature dimensionality reduction, which strongly impacts classification accuracy. Experiments show that our method outperforms previous steganalysis methods. For instance, when the probability of false alarm is fixed at 1%, the stegoimage detection probability of our algorithm exceeds that of its closest competitor by at least 15% and up to 50%

Hiding a Large Amount of Data with High Security Using Steganography Algorithm

Abstract: This study deals with constructing and implementing new algorithm based on hiding a large amount of data (image, audio, text) file into color BMP image. We have been used adaptive image filtering and adaptive image segmentation with bits replacement on the appropriate pixels. These pixels are selected randomly rather than sequentially by using new concept defined by main cases with their sub cases for each byte in one pixel. This concept based on both visual and statistical. According to the steps of design, we have been concluded 16 main cases with their sub cases that cover all aspects of the input data into color bitmap image. High security layers have been proposed through three layers to make it difficult to break through the encryption of the input data and confuse steganalysis too. Our results against statistical and visual attacks are discussed and make comparison with the previous Steganography algorithms like S-Tools. We show that our algorithm can embed efficiently a large amount of data that has been reached to 75% of the image size with high quality of the output.

Data Hiding: Current Status and Key Issues

Abstract: Image steganography is a covert communication method that uses an image as the cover to hide the truth from potential attackers that some secret message hidden in the image is being transported. When we appreciate the astonishing beauty of a world famous picture in its digital form on the computer, it is hard to imagine that the picture might actually be working as a messenger, carrying some invisible important secret message along with it. In other words, steganography is a collection of cryptographic techniques that provide protection to the secret message by offering it the appearance of an image. In this survey paper, our focus is on the development and current status of steganographic techniques for grayscale images. We shall separately introduce schemes with high hiding capacities and schemes with high imperceptibility. The advantages and disadvantages of those schemes will be closely analyzed, offering directions for our future research efforts.

Implementation of LSB Steganography and Its Evaluation for Various Bits

Abstract: Steganography is the art of hiding information in information is gaining momentum as it scores over cryptography because it enables to embedd the secret message to cover images. Steganographic techniques offer more promise in digital image processing. The Least Significant Bit embedding technique suggests that data can be hidden in the least significant bits of the cover image and the human eye would be unable to notice the hidden image in the cover file. This technique can be used for hiding images in 24-bit, 8-bit or gray scale format. We emphasize strongly on image Steganography providing a strong focus on the LSB techniques in image Steganography. This paper explains the LSB embedding technique and presents the evaluation results for 2,4,6 Least significant bits for a .png file and a .bmp file.

DNA-based watermarks using the DNA-Crypt algorithm.

Abstract: The aim of this paper is to demonstrate the application of watermarks based on DNA sequences to identify the unauthorized use of genetically modified organisms (GMOs) protected by patents. Predicted mutations in the genome can be corrected by the DNA-Crypt program leaving the encrypted information intact. Existing DNA cryptographic and steganographic algorithms use synthetic DNA sequences to store binary information however, although these sequences can be used for authentication, they may change the target DNA sequence when introduced into living organisms. The DNA-Crypt algorithm and image steganography are based on the same watermark-hiding principle, namely using the least significant base in case of DNA-Crypt and the least significant bit in case of the image steganography. It can be combined with binary encryption algorithms like AES, RSA or Blowfish. DNA-Crypt is able to correct mutations in the target DNA with several mutation correction codes such as the Hamming-code or the WDH-code. Mutations which can occur infrequently may destroy the encrypted information, however an integrated fuzzy controller decides on a set of heuristics based on three input dimensions, and recommends whether or not to use a correction code. These three input dimensions are the length of the sequence, the individual mutation rate and the stability over time, which is represented by the number of generations. In silico experiments using the Ypt7 in Saccharomyces cerevisiae shows that the DNA watermarks produced by DNA-Crypt do not alter the translation of mRNA into protein. The program is able to store watermarks in living organisms and can maintain the original information by correcting mutations itself. Pairwise or multiple sequence alignments show that DNA-Crypt produces few mismatches between the sequences similar to all steganographic algorithms.

Histogram-Based Audio Watermarking Against Time-Scale Modification and Cropping Attacks

Abstract: In audio watermarking area, the robustness against desynchronization attacks, such as TSM (Time-Scale Modification) and random cropping operations, is still one of the most challenging issues. In this paper, we present a multibit robust audio watermarking solution for such a problem by using the insensitivity of the audio histogram shape and the modified mean to TSM and cropping operations. We address the insensitivity property in both mathematical analysis and experimental testing by representing the histogram shape as the relative relations in the number of samples among groups of three neighboring bins. By reassigning the number of samples in groups of three neighboring bins, the watermark sequence is successfully embedded. In the embedding process, the histogram is extracted from a selected amplitude range by referring to the mean in such a way that the watermark will be able to be resistant to amplitude scaling and avoid exhaustive search in the extraction process. The watermarked audio signal is perceptibly similar to the original one. Experimental results demonstrate that the hidden message is very robust to TSM and random cropping attacks, and also has a satisfactory robustness for those common audio signal processing operations.

A Novel Arabic Text Steganography Method Using Letter Points and Extensions

Abstract: This paper presents a new steganography approach suitable for Arabic texts. It can be classified under steganography feature coding methods. The approach hides secret information bits within the letters benefiting from their inherited points. To note the specific letters holding secret bits, the scheme considers the two features, the existence of the points in the letters and the redundant Arabic extension character. We use the pointed letters with extension to hold the secret bit ‘one’ and the un-pointed letters with extension to hold ‘zero’. This steganography technique is found attractive to other languages having similar texts to Arabic such as Persian and Urdu. Keywords — Arabic text, Cryptography, Feature coding, Information security, Text steganography, Text watermarking.

Steganalysis of Embedding in Two Least-Significant Bits

Abstract: This paper proposes steganalysis methods for extensions of least-significant bit (LSB) overwriting to both of the two lowest bit planes in digital images: there are two distinct embedding paradigms. The author investigates how detectors for standard LSB replacement can be adapted to such embedding, and how the methods of "structural steganalysis", which gives the most sensitive detectors for standard LSB replacement, may be extended and applied to make more sensitive purpose-built detectors for two bit plane steganography. The literature contains only one other detector specialized to detect replacement multiple bits, and those presented here are substantially more sensitive. The author also compares the detectability of standard LSB embedding with the two methods of embedding in the lower two bit planes: although the novel detectors have a high accuracy from the steganographer's point of view, the empirical results indicate that embedding in the two lowest bit planes is preferable (in some cases, highly preferable) to embedding in one

Pattern-Based Data Hiding for Binary Image Authentication by Connectivity-Preserving

Abstract: In this paper, a novel blind data hiding method for binary images authentication aims at preserving the connectivity of pixels in a local neighborhood is proposed. The "flippability" of a pixel is determined by imposing three transition criteria in a 3 times 3 moving window centered at the pixel. The "embeddability" of a block is invariant in the watermark embedding process, hence the watermark can be extracted without referring to the original image. The "uneven embeddability" of the host image is handled by embedding the watermark only in those "embeddable" blocks. The locations are chosen in such a way that the visual quality of the watermarked image is guaranteed. Different types of blocks are studied and their abilities to increase the capacity are compared. The problem of how to locate the "embeddable" pixels in a block for different block schemes is addressed which facilitates the incorporation of the cryptographic signature as the hard authenticator watermark to ensure integrity and authenticity of the image. Discussions on the security considerations, visual quality against capacity, counter measures against steganalysis and analysis of the computational load are provided. Comparisons with prior methods show superiority of the proposed scheme

A New Steganographic Method for Data Hiding in Microsoft Word Documents by a Change Tracking Technique

Abstract: A new steganographic method for data hiding in Microsoft Word documents by a change tracking technique is proposed. The data embedding is disguised such that the stegodocument appears to be the product of a collaborative writing effort. Text segments in the document are degenerated, mimicking to be the work of an author with inferior writing skills, with the secret message embedded in the choices of degenerations. The degenerations are then revised with the changes being tracked, making it appear as if a cautious author is correcting the mistakes. The change tracking information contained in the stegodocument allows the original cover, the degenerated document, and, hence, the secret message to be recovered. The extra change tracking information added during message embedding is vital in a normal collaboration scenario, and so hinders ignorant removals by skeptics. Experiments demonstrate the feasibility of the proposed method

A Capacity Result for Batch Steganography

Abstract: The problems of batch steganography and pooled steganalysis, proposed in , generalize the problems of hiding and detecting hidden data to multiple covers It was conjectured that, given covers of uniform capacity and a quantitative steganalysis method satisfying certain assumptions, "secure" steganographic capacity is proportional only to the square root of the number of covers We now prove that, with respect to a natural definition of secure capacity, and in a suitably asymptotic sense, this conjecture is true This is in sharp contrast to capacity results for noisy channels

Noise Features for Image Tampering Detection and Steganalysis

Abstract: With increasing availability of low-cost image editing softwares, the authenticity of digital images can no longer be taken for granted. Digital images have also been used as cover data for transmitting secret information in the field of steganography. In this paper, we introduce a new set of features for multimedia forensics to determine if a digital image is an authentic camera output or if it has been tampered or embedded with hidden data. We perform such image forensic analysis employing three sets of statistical noise features, including those from denoising operations, wavelet analysis, and neighborhood prediction. Our experimental results demonstrate that the proposed method can effectively distinguish digital images from their tampered or stego versions.

Improving Embedding Efficiency of Covering Codes for Applications in Steganography

Abstract: In image steganography, each pixel can carry a ternary message by choosing adding/subtracting one to/from the gray value. Although ternary covering functions can provide embedding efficiency higher than binary ones, it is necessary to convert the binary message into a ternary format. We propose a novel method that improves the embedding efficiency of binary covering functions by fully exploiting the information contained in the choice of addition or subtraction in the embedding. The improved scheme can perform equally well with, or even outperform, ternary covering functions without ternary conversion of the message.

A Double Layered “Plus-Minus One” Data Embedding Scheme

Abstract: In image steganography, a pixel can carry secret bits by choosing adding/subtracting one to/from the gray value. This kind of "plusmn1 steganography" can hide a longer message than simple LSB embedding. We propose a double-layered embedding method for implementing "plusmn1 steganography," in which binary covering codes and wet paper codes are used to hide messages in the LSB plane and the second LSB plane, respectively. We show that this method can achieve the upper bound on the embedding efficiency of "plusmn1 steganography" when the employed binary covering codes reach the upper bound on that of LSB steganography. Applications using random and structured covering codes show that the new method outperforms previous ones and can approach the upper bound.

Text Steganography in SMS

Abstract: One of the services used in mobile phone is the short message service (SMS) which is widely used by the public in all parts of the world especially in Asia and Europe. This service enables people to write and exchange short messages via mobile phone. Due to the limited size of SMS, lack of a proper keyboard on the mobile phone and to improve the speed of typing, new abbreviations have been invented for different words and phrases which has lead to the invention of a new language called SMS-texting. One of the main issues in communication is information security and privacy. There are many methods for secret communication and many researchers are working on steganography. In steganography the data is hidden in a cover media such as picture or text. The present paper offers a new method for secret exchange of information through SMS by using and developing abbreviation text steganography with the use of the invented language of SMS-texting. This project has been implemented by J2ME (Java 2 Micro Edition) programming language and tested on a Nokia N71 mobile phone.

Arabic Diacritics based Steganography

Abstract: New steganography methods are being proposed to embed secret information into text cover media in order to search for new possibilities employing languages other than English. This paper utilizes the advantages of diacritics in Arabic to implement text steganography. Diacritics - or Harakat - in Arabic are used to represent vowel sounds and can be found in many formal and religious documents. The proposed approach uses eight different diacritical symbols in Arabic to hide binary bits in the original cover media. The embedded data are then extracted by reading the diacritics from the document and translating them back to binary.

Steganalysis for LSB Matching in Images with High-frequency Noise

Abstract: Considerable progress has been made in the detection of steganographic algorithms based on replacement of the least significant bit (LSB) plane. However, if LSB matching, also known as -1 embedding, is used, the detection rates are considerably reduced. In particular, since LSB embedding is modeled as an additive noise process, detection is especially poor for images that exhibit high-frequency noise - the high-frequency noise is often incorrectly thought to be indicative of a hidden message. To overcome this, we propose a targeted steganalysis algorithm that exploits the fact that after LSB matching, the local maxima of an images graylevel or color histogram decrease and the local minima increase. Consequently, the sum of the absolute differences between local extrema and their neighbors in the intensity histogram of stego images will be smaller than for cover images. Experimental results on two datasets, each of 2000 images, demonstrate that this method has superior results compared with other recently proposed algorithms when the images contain high-frequency noise, e.g. never-compressed imagery such as high-resolution scans of photographs and video. However, the method is inferior to the prior art when applied to decompressed imagery with little or no high-frequency noise.

(Computer Vision and Image Understanding,107(3):183-194)A New Steganographic Method for Color and Grayscale Image Hiding

Abstract: In this paper, we present a steganographic method for embedding a color or a grayscale image in a true color image. Three types of secret images can be carried by the proposed method: hiding a color secret image, hiding a palette-based 256-color secret image, and hiding a grayscale image in a true color image. Secret data are protected by the conventional crypto system DES. We compare the image quality and hiding capacity of the proposed method with those of the scheme in Lin et al.'s scheme. According to the experimental results, the image quality of the proposed method is better than that of the Lin et al.'s scheme. In addition, annotation data can be hidden with the secret image in the host image. The hiding capacity of the proposed method is greater than that of other compared schemes. The experimental results show that the proposed method is a secure steganographic method that provides high hiding capacity and good image quality.

A Steganographic Method with High Embedding Capacity by Improving Exploiting Modification Direction

Abstract: We propose an effective data hiding method based on the EMD embedding scheme proposed by Zhang et al. in order to enhance the embedding capacity. The main idea of our proposed scheme is to convert secret binary messages into a sequence of digits in an 8-ary notational system. Each secret digit is embedded into two cover pixels by modifying the least significant bits (LSBs). As the experimental results show, the embedding bit-rate of our scheme is 1.5 times better than the EMD embedding scheme. In a word, we propose a high-quality and high-capacity data hiding method that can ensure the stego-image quality and security.

Image based Steganography and Cryptography

Abstract: In this paper we describe a method for integrating together cryptography and steganography through image processing. In particular, we present a system able to perform steganography and cryptography at the same time using images as cover objects for steganography and as keys for cryptography. We will show such system is an effective steganographic one (making a comparison with the well known F5 algorithm) and is also a theoretically unbreakable cryptographic one (demonstrating its equivalence to the Vernam Cipher).