Showing papers on "Steganography published in 2000"

Information-theoretic analysis of information hiding

Abstract: An information-theoretic analysis of information hiding is presented, forming the theoretical basis for design of information-hiding systems. Information hiding is an emerging research area which encompasses applications such as copyright protection for digital media, watermarking, fingerprinting, steganography, and data embedding. In these applications, information is hidden within a host data set and is to be reliably communicated to a receiver. The host data set is intentionally corrupted, but in a covert way, designed to be imperceptible to a casual analysis. Next, an attacker may seek to destroy this hidden information, and for this purpose, introduce additional distortion to the data set. Side information (in the form of cryptographic keys and/or information about the host signal) may be available to the information hider and to the decoder. We formalize these notions and evaluate the hiding capacity, which upper-bounds the rates of reliable transmission and quantifies the fundamental tradeoff between three quantities: the achievable information-hiding rates and the allowed distortion levels for the information hider and the attacker. The hiding capacity is the value of a game between the information hider and the attacker. The optimal attack strategy is the solution of a particular rate-distortion problem, and the optimal hiding strategy is the solution to a channel-coding problem. The hiding capacity is derived by extending the Gel'fand-Pinsker (1980) theory of communication with side information at the encoder. The extensions include the presence of distortion constraints, side information at the decoder, and unknown communication channel. Explicit formulas for capacity are given in several cases, including Bernoulli and Gaussian problems, as well as the important special case of small distortions. In some cases, including the last two above, the hiding capacity is the same whether or not the decoder knows the host data set. It is shown that many existing information-hiding systems in the literature operate far below capacity.

High capacity image steganographic model

Abstract: Steganography is an ancient art of conveying messages in a secret way that only the receiver knows the existence of a message. So a fundamental requirement for a steganographic method is imperceptibility; this means that the embedded messages should not be discernible to the human eye. There are two other requirements, one is to maximise the embedding capacity, and the other is security. The least-significant bit (LSB) insertion method is the most common and easiest method for embedding messages in an image. However, how to decide on the maximal embedding capacity for each pixel is still an open issue. An image steganographic model is proposed that is based on variable-size LSB insertion to maximise the embedding capacity while maintaining image fidelity. For each pixel of a grey-scale image, at least four bits can be used for message embedding. Three components are provided to achieve the goal. First, according to contrast and luminance characteristics, the capacity evaluation is provided to estimate the maximum embedding capacity of each pixel. Then the minimum-error replacement method is adapted to find a grey scale as close to the original one as possible. Finally, the improved grey-scale compensation, which takes advantage of the peculiarities of the human visual system, is used to eliminate the false contouring effect. Two methods, pixelwise and bitwise, are provided to deal with the security issue when using the proposed model. Experimental results show effectiveness and efficiency of the proposed model.

Cryptography with DNA binary strands

Abstract: Biotechnological methods can be used for cryptography. Here two different cryptographic approaches based on DNA binary strands are shown. The first approach shows how DNA binary strands can be used for steganography, a technique of encryption by information hiding, to provide rapid encryption and decryption. It is shown that DNA steganography based on DNA binary strands is secure under the assumption that an interceptor has the same technological capabilities as sender and receiver of encrypted messages. The second approach shown here is based on steganography and a method of graphical subtraction of binary gel-images. It can be used to constitute a molecular checksum and can be combined with the first approach to support encryption. DNA cryptography might become of practical relevance in the context of labelling organic and inorganic materials with DNA ‘barcodes’. © 2000 Elsevier Science Ireland Ltd. All rights reserved.

Information Hiding: Steganography and Watermarking-Attacks and Countermeasures: Steganography and Watermarking - Attacks and Countermeasures

Abstract: Information Hiding: Steganography and Watermarking - Attacks and Countermeasures deals with information hiding. With the proliferation of multimedia on the Internet, information hiding addresses two areas of concern: privacy of information from surveillance (steganography) and protection of intellectual property (digital watermarking). Steganography (literally, covered writing) explores methods to hide the existence of hidden messages. These methods include invisible ink, microdot, digital signature, covert channel, and spread spectrum communication. Digital watermarks represent a commercial application of steganography. Watermarks can be used to track the copyright and ownership of electronic media. In this volume, the authors focus on techniques for hiding information in digital media. They analyze the hiding techniques to uncover their limitations. These limitations are employed to devise attacks against hidden information. The goal of these attacks is to expose the existence of a secret message or render a digital watermark unusable. In assessing these attacks, countermeasures are developed to assist in protecting digital watermarking systems. Understanding the limitations of the current methods will lead us to build more robust methods that can survive various manipulation and attacks. The more information that is placed in the public's reach on the Internet, the more owners of such information need to protect themselves from theft and false representation. Systems to analyze techniques for uncovering hidden information and recover seemingly destroyed information will be useful to law enforcement authorities in computer forensics and digital traffic analysis. Information Hiding: Steganography and Watermarking - Attacks and Countermeasures presents the authors' research contributions in three fundamental areas with respect to image-based steganography and watermarking: analysis of data hiding techniques, attacks against hidden information, and countermeasures to attacks against digital watermarks. Information Hiding: Steganography and Watermarking e Attacks and Countermeasures is suitable for a secondary text in a graduate level course, and as a reference for researchers and practitioners in industry.

DNA-based steganography

Abstract: The present invention relates to a stenographic method for concealing coded messages in DNA. The method of the invention comprises concealing a DNA encoded message within a genomic DNA sample followed by further concealment of the DNA sample to a microdot. The present invention further provides a method for the use of genomic steganography to mark and authenticate objects of interest.

Audio or video steganography

Abstract: An input content signal—representing audio or video—is encoded to hide plural-bit auxiliary data therein. The process generates an intermediate signal that is a function of (a) the plural-bit auxiliary data, and (b) data related to human perception attributes of the content signal. This intermediate signal is then summed with the content signal to effect encoding. The plural-bit auxiliary data can include copy control data, i.e., data that can be sensed by a consumer electronic device and used to disable a copying operation. The intermediate signal may include a pseudorandom key signal so as to obscure the encoding and require knowledge of a corresponding key at the decoder to extract the auxiliary data from the encoded content. In some embodiments, calibration data is encoded in the content signal with the auxiliary data. This calibration data desirably has known properties (e.g., spectral attributes, data content, etc.) facilitating its identification in the encoded content signal. The encoding is desirably robust against various forms of content degradation, e.g., lossy compression/decompression, scaling, resampling, conversion from digital to analog and back again, etc., so that the auxiliary data can be detected from the content notwithstanding such corruption.

Generalized watermarking attack based on watermark estimation and perceptual remodulation

Abstract: Digital image watermarking has become a popular technique for authentication and copyright protection. For verifying the security and robustness of watermarking algorithms, specific attacks have to be applied to test them. In contrast to the known Stirmark attack, which degrades the quality of the image while destroying the watermark, this paper presents a new approach which is based on the estimation of a watermark and the exploitation of the properties of Human Visual System (HVS). The new attack satisfies two important requirements. First, image quality after the attack as perceived by the HVS is not worse than the quality of the stego image. Secondly, the attack uses all available prior information about the watermark and cover image statistics to perform the best watermark removal or damage. The proposed attack is based on a stochastic formulation of the watermark removal problem, considering the embedded watermark as additive noise with some probability distribution. The attack scheme consists of two main stages: (1) watermark estimation and partial removal by a filtering based on a Maximum a Posteriori (MAP) approach; (2) watermark alteration and hiding through addition of noise to the filtered image, taking into account the statistics of the embedded watermark and exploiting HVS characteristics. Experiments on a number of real world and computer generated images show the high efficiency of the proposed attack against known academic and commercial methods: the watermark is completely destroyed in all tested images without altering the image quality. The approach can be used against watermark embedding schemes that operate either in coordinate domain, or transform domains like Fourier, DCT or wavelet.

A secure data hiding scheme for two-color images

Abstract: In this paper we propose a new steganography scheme for hiding a piece of critical information in a host binary image (such as facsimiles). A secret key and a weight matrix are used to protect the hidden data. Given an image block of size m/spl times/n, our scheme can hide as many as [log/sub 2/(mn+1)] bits of data in the image by changing at most 2 bits in the image. This scheme, as compared to an existing scheme by M. Y. Wu et al. 1998), can provide higher security, embed more data, and maintain higher quality of the host image.

Data hiding in multimedia - theory and applications

Abstract: DATA HIDING IN MULTIMEDIA THEORY AND APPLICATIONS by Mahalingam Ramkumar Multimedia data hiding or steganography is a means of communication using subliminal channels. The resource for the subliminal communication scheme is the distortion of the original content that can be tolerated. This thesis addresses two main issues of steganographic communication schemes: 1. How does one maximize the distortion introduced without affecting fidelity of the content? 2. How does one efficiently utilize the resource (the distortion introduced) for communicating as many bits of information as possible? In other words, what is a good signaling strategy for the subliminal communication scheme? Close to optimal solutions for both issues are analyzed. Many techniques for the issue for maximizing the resource, viz. the distortion introduced imperceptibly in images and video frames, are proposed. Different signaling strategies for steganographic communication are explored, and a novel signaling technique employing a floating signal constellation is proposed. Algorithms for optimal choices of the parameters of the signaling technique are presented. Other application specific issues like the type of robustness needed are taken into consideration along with the established theoretical background to design optimal data hiding schemes. In particular, two very important applications of data hiding are addressed data hiding for multimedia content delivery, and data hiding for watermarking (for proving ownership). A robust watermarking protocol for unambiguous resolution of ownership is proposed. DATA HIDING IN MULTIMEDIA THEORY AND APPLICATIONS by Mahalingam Ramkumar A. Dissertation Submitted to the Faculty of New Jersey Institute of Technology in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Department of Electrical and Computer Engineering

Copy protection of digital data combining steganographic and cryptographic techniques

Abstract: A method for combining transfer functions with predetermined key creation In one embodiment, digital information, including a digital sample and format information, is protected by identifying and encoding a portion of the format information Encoded digital information, including the digital sample and the encoded format information generated to protect the original digital information In another embodiment, a digital signal, including digital samples in a file format having an inherent granularity, is protected by creating a predetermined key The predetermined key is comprised of a transfer function-based mask set to manipulate data at the inherent granularity of the file format of the underlying digitized samples

An Information-Theoretic Model for Steganography.

Abstract: An information-theoretic model for steganography with a passive adversary is proposed. The adversary’s task of distinguishing between an innocent cover message C and a modified message S containing hidden information is interpreted as a hypothesis testing problem. The security of a steganographic system is quantified in terms of the relative entropy (or discrimination) between the distributions of C and S, which yields bounds on the detection capability of any adversary. It is shown that secure steganographic schemes exist in this model provided the covertext distribution satisfies certain conditions. A universal stegosystem is presented in this model that needs no knowledge of the covertext distribution, except that it is generated from independently repeated experiments.

Image Steganography for Hidden Communication

Abstract: : Modern steganographic methods, which conceal the existence of communication, are needed to exploit contemporary modes of information exchange. Measures of performance for these methods are essential to compare specific algorithms and determine appropriate uses. This report develops a methodology for steganographic data hiding. The methodology encompasses derivation of a general theory of steganographic communication, including theoretical capacity hounds, and design of an actual data-hiding technique that used digital imagery as a cover. The technique promotes maximization of payload, allows error-free recovery of embedded date, and provides some resilience to removal while concealing the existence of the embedded information from the observer and the observer's resources (e.g., computer).

Moiré cryptography

Abstract: As already pointed out by other researchers, one of the central problems with applicability of visual cryptography is the random nature of its secret shares. It makes secret shares not suited for carrying or for transmission over an open channel. In this paper, we apply concepts of steganography to create secret sharing schemes whose shares are realistically looking images. Our new technique is based on an idea of employing Moir e patterns for producing images. The advantage of this scheme over others is that it does not require a complicated algorithm, thus a computer, to decrypt the ciphertext. The cleartext can be read simply by putting the ciphertexts one onto the other. We therefore give a solution to the above mentioned problem with a novel type of visual secret sharing schemes, whose secrecy and anonymity are both satis ed.

Steganography for a low bit-rate wavelet based image coder

Abstract: This approach inserts a hidden steganographic message into a base layer transmission of a zerotree based wavelet coder. The message is hidden in sign/bit values of insignificant children of the detail subbands in nonsmooth regions of the image. The HC-RTOT coder is used to determine what regions of the image that the message can be embedded in. The coder also determines which wavelet coefficients in the detail subbands of these regions are used for messaging by the use of a steganographic mask which can be unique for each transmission occurrence of the image. The advantage of this approach is the ability to send steganographic messages in lossy environments with a robustness against detection or attack. Preliminary results indicate that the message can be sent with a 4%-10% overhead capacity of the base layer bitstream (0.04-0.1 bpp) depending on several variations of the method.

Image capture device with steganographic data embedding

Abstract: An image capture device is provided with processing circuitry that steganographically embeds plural-bit auxiliary data within the captured image data. The embedding may be accomplished by adding a low level noise signal to the image data, where the noise signal has the auxiliary data encoded therein. Image data output by the device thus conveys auxiliary data that can be used for a variety of purposes.

A distributed detection framework for Steganalysis

Abstract: Many watermarking algorithms have been proposed and studied for their robustness and other properties. But, there has been little effort is analyzing these algorithms for their vulnerability against detection by an adversary. As a general philosophy for robust watermarking the host signal and the watermarked signal are well separated in a statistical distance sense. This very nature can be exploited by an adversary to easily detect the watermark and perhaps remove it. We argue that the ability of a watermark to avoid detection by an adversary is a key factor that needs more attention. In this paper, we propose a framework, based on a distributed detection technique, that can be used by the adversary to study signals for the presence/absence of watermarks. We choose a particular spatial domain image watermarking algorithm and explain how the proposed framework can be applied to detect the watermark with very little knowledge about the watermark insertion procedure. The false alarm probability can be optimally traded-off with the probability of detection using the receiver operating characteristic function.

Exploring steganography for low bit rate wavelet based coder in image retrieval system

Abstract: An image retrieval system that provides an efficient retrieval, management and transmission of selected image(s) from the database is proposed. The key point of research is utilizing a steganographic technique to achieve the efficient use of resources by embedding attributes into the image contents. To avoid the degradation of image quality, the attributes are invisibly embedded in the edge representations of the compressed domain of the ZTE (zerotree entropy)/modified SPIHT (set partitioning in hierarchical trees) wavelet based coder. The evaluations of the proposed algorithm have shown several significant advantages. For example, (1) fast transmission of the retrieved image to the receiver, (2) it allows searching based on the retrieval images, (3) no reprocessing of the attributes for other applications, (4) no extra bits required for the conventional thumbnail and (5) no extra bits for the attributes.

Video steganography methods avoiding introduction of fixed pattern noise

Abstract: Video is steganographically encoded to convey a plural bit message without introducing apparent fixed pattern noise. The video comprises plural frames, each of which includes plural rows of video data. The encoding effects a pattern of changes to a row of original video to yield a row of encoded video. But that row—in a subsequent frame (e.g., the next frame)—is changed by a different pattern. Fixed pattern artifacts are thus avoided. In some arrangements, the frames convey different messages. In others, the frames convey the same message, but the apparent effect is changed by different noise data used in the encoding.

Topological Ordered Color Table for BPCS Steganography Using Indexed Color Images

Abstract: Image index tables values generally give the best possible representation of the color information of the image. However, no consideration is given to the arrangement of the color table itself. Thus, depending on the image, pixels with similar colors may have different index values and can therefore have considerably different index binary makeups. Consequently, regions of similarly colored indexed pixels can be noise-like at the bitplane level while the output colors themselves may imply simple bitplane patterns. BPCS image steganography hides information in images based on the principle that if regions in a bitplane are noise-like, those regions can be replaced with noise-like secret data. Therefore, applying traditional BPCS steganography to indexed image data results in drastic visible changes to the image. To overcome this problem, we used a self-organizing neural network to reorder the index table, based on samples from the image, such that similar colors in the index table are near each other with respect to their index values. As a result, regions with similar color information have only slight binary differences at the bitplane level, whereas regions with mixed color information will have considerable binary differences. Using this technique, we can embed secret data that is 15 to 35 percent the size of the image with little or no noticeable degradation in the image.

Method for steganographic encoding

Abstract: A method is presented for encoding auxiliary information in digital images which enables the encoding of both compact auxiliary information specific to a given image and a secret message into a given image such that the hidden message contained therein is only revealed in such a way that neither the image itself nor the auxiliary information alone are sufficient to reveal the secret message. Specifically, a method for encoding an auxiliary message in a digital image, is presented having the first step of creating a set of Training Vectors from all N×N windowed observations of a digital image (D) and corresponding pixels of a message (I). Then, statistically estimating a function T from the set of Training Vectors which map the N×N windowed observations of the digital image (D) to the corresponding pixels of the message (I); and writing out the statistically estimated function T as a representation of the hidden message.

Data Hiding via Steganographic Image Transformation

Abstract: This paper presents a new data hiding scheme via steganographic image transformation, which is different from conventional data hiding techniques. The transformation is achieved in the frequency domain and the concept of Fourier filtering method is used. An input image is transformed into a fractal image, which can be used in Computer Graphic (CG) applications. One of the main advantages of this scheme is the amount of data to be hidden (embedded) is equal to that of the host signal (generated fractal image) while it is in general limited in the conventional data hiding schemes. Also both the opened fractal image and the hidden original one can be properly used depending on the situation. Unauthorized users will not notice the “secret” original image behind the fractal image, but even if they know that there is a hidden image it will be difficult for them to estimate the original image from the transformed image. Only authorized users who know the proper keys can regenerate the original image. The proposed method is applicable not only as a security tool for multimedia contents on web pages but also as a steganographic secret communication method through fractal images. key words: steganography, data hiding, multimedia, fractal, Fourier filtering method, fBm (fractional Brownian motion), computer graphics

FFT based signaling for multimedia steganography

Abstract: This paper addresses good choices for the signaling method for multimedia steganography, or data hiding. A novel FFT based signaling method, with many properties that make it especially suitable for steganographic applications is proposed. The use of FFT permits large codebook sizes, without drastically increasing the computational complexity.

Floating signal constellations for multimedia steganography

Abstract: Conventional spread spectrum communication methods essentially map a discrete symbol from an alphabet to a length-N real valued sequence, which represents a point in the N-dimensional signal constellation. The real valued sequence is in turn transmitted over a communications channel. However, communication schemes for the purpose of multimedia steganography (or data hiding) have to transmit the real valued sequence corresponding to a point in the signal constellation superimposed on the original or cover content (without affecting the fidelity of the original content noticeably). The detector therefore, has to estimate the origin of the signal constellation, and thereafter proceed to decode the transmitted symbol. In this paper, we explore some efficient solutions for signaling methods employing floating signal constellations.

How to bypass the Wassenaar arrangement: a new application for watermarking

Abstract: The scope of this article is to clarify the current legal and political situation related to electronic surveillance on the one hand, and to export regulations for encryption software on the other hand. We will look at different international agreements, such as the UKUSA agreement and the Wassenaar arrangement, and elaborate on current encryption techniques falling under these regulations. This discussion is then followed by introducing the basic concepts of steganography and digital watermarking which could be used for secret communication. As a consequence, we propose an original way to legally bypass the international export regulations using these technologies. To this end a new watermarking technique is proposed, which is robust to JPEG2000 compression and provides a good channel capacity. The efficiency of the proposed technique is analyzed by means of simulations to allow for secure communications.

Printed matter and information security system using the printed matter

Abstract: PROBLEM TO BE SOLVED: To provide a steganography technique using a printed image as its medium, to prevent both forgery and illegal use of a printed matter and to embed the secret information in a printed matter for preserving and transmitting secretly the information. SOLUTION: The information data are embedded in the image or pattern data printed on an object to be printed by the steganography method so that the information data are kept in a completely secret state by means of a printed matter. Then the information data are embedded in an original by the steganography method and this original is printed on the object to be printed for producing a printed matter. The image or pattern data are read out of the printed matter by means of a scanner and the original is restored. The secret information data are extracted from the restored original and outputted as the images, music, voices and characters. As the printed image or pattern data are used as a medium, the information is embedded in an image or a pattern that looks like just a mere printed matter and then can be extracted as necessary. As a result, the secret information is kept as a printed matter and also can be safely transmitted to another place.

A Steganographic Framework for Reference Colour Based Encoding and Cover Image Selection

Abstract: Steganography is a method of communication which hides the existence of the communication from a third party.The employment of steganographic techniques depends on various demands, which will be derived and considered. This paper regards different aspects of digital images. These are representation, storage and as a result also suitability for their use in steganography. Based upon this, some criteria for the choice of suitable cover images are pointed out. A new technical steganographic system, which uses reference colours as starting point for embedding and extraction of information has been developed and will be described. This system can be adapted flexibly to different requirements and considers the human visual system as well as the derived statements for potential cover images. Results are described which justify the new approach.

Methods and systems for inserting watermarks in digital signals

Abstract: The presently claimed invention relates generally to steganographic encoding and digital watermarking. One claim recites a method including identifying at least one change to a digital signal that will be affected by a filter; and encoding at least one digital watermark so the digital watermark survives the changes introduced by the filter. The “digital signal” may represent audio or video. Another claim recites a system including a processor and an encoder. The processor identifies an area or portion of a digital signal that will be affected by a digital filter. The encoder encodes the at least one digital watermark in the digital signal, the encoder encoding the at least one digital watermark so as to avoid the at least one area or portion of the digital signal that is identified by said processor. Of course, other combinations are provided and claimed as well.

Information hiding : third International Workshop, IH'99, Dresden, Germany, September 29-October 1, 1999 : proceedings

Abstract: Fundamentals of Steganography.- An Information-Theoretic Approach to Steganography and Watermarking.- One-Time Hash Steganography.- Steganography: Paradigms and Examples.- Steganography Secure against Cover-Stego-Attacks.- Secure Steganographic Methods for Palette Images.- Attacks on Steganographic Systems.- Beyond Symmetric Steganography.- Developments in Steganography.- An Asymmetric Public Detection Watermarking Technique.- Zero Knowledge Watermark Detection.- Watermarking: Proving Ownership.- Proving Ownership of Digital Content.- Error- and Collusion-Secure Fingerprinting for Digital Data.- Watermarking: Detection and Decoding.- Computing the Probability of False Watermark Detection.- Optimum Decoding of Non-additive Full Frame DFT Watermarks.- Watermark Detection after Quantization Attacks.- Content-Based Watermarking for Image Authentication.- Watermarking: Embedding Techniques.- Fast Robust Template Matching for Affine Resistant Image Watermarks.- A Stochastic Approach to Content Adaptive Digital Image Watermarking.- Performance Improvement of Spread Spectrum Based Image Watermarking Schemes through M-ary Modulation.- Watermarking: New Designs and Applications.- On the Design of a Watermarking System: Considerations and Rationales.- A Bayesian Approach to Affine Transformation Resistant Image and Video Watermarking.- Enhanced Intellectual Property Protection for Digital Circuits on Programmable Hardware.- Watermarking: Improving Robustness.- Robust Watermarking for Images Based on Color Manipulation.- Recovery of Watermarks from Distorted Images.- Cocktail Watermarking on Images.- Watermarking and Software Protection.- Hiding Signatures in Graph Coloring Solutions.- Robust Object Watermarking: Application to Code.- Software DisEngineering: Program Hiding Architecture and Experiments.- The Difficulty of Separating Private and Public Information.- Chaffing at the Bit.- An Entropy-Based Framework for Database Inference.- Covert Information Transmission through the Use of Standard Collision Resolution Algorithms.- The Cocaine Auction Protocol: On the Power of Anonymous Broadcast.- Stego-Engineering.- Protecting Secret Keys in a Compromised Computational System.- StegFS: A Steganographic File System for Linux.- Nonbinary Audio Cryptography.