Showing papers on "Steganography tools published in 2006"

An evaluation of image based steganography methods

Abstract: Steganography is a process that involves hiding a message in an appropriate carrier for example an image or an audio file. The carrier can then be sent to a receiver without anyone else knowing that it contains a hidden message. This is a process, which can be used for example by civil rights organisations in repressive states to communicate their message to the outside world without their own government being aware of it. Less virtuously it can be used by terrorists to communicate with one another without anyone else's knowledge. In both cases the objective is not to make it difficult to read the message as cryptography does, it is to hide the existence of the message in the first place possibly to protect the courier. The initial aim of this study was to investigate steganography and how it is implemented. Based on this work a number of common methods of steganography could then be implemented and evaluated. The strengths and weaknesses of the chosen methods can then be analysed. To provide a common frame of reference all of the steganography methods implemented and analysed used GIF images. Seven steganography methods were implemented. The methods were chosen for their different strengths in terms of resistance to different types of steganalysis or their ability to maximise the size of the message they could store. All of the methods used were based on the manipulation of the least significant bits of pixel values or the rearrangement of colours to create least significant bit or parity patterns, which correspond to the message being hidden.

Batch steganography and pooled steganalysis

Abstract: Conventional steganalysis aims to separate cover objects from stego objects, working on each object individually. In this paper we investigate some methods for pooling steganalysis evidence, so as to obtain more reliable detection of steganography in large sets of objects, and the dual problem of hiding information securely when spreading across a batch of covers. The results are rather surprising: in many situations, a steganographer should not spread the embedding across all covers, and the secure capacity increases only as the square root of the number of objects. We validate the theoretical results, which are rather general, by testing a particular type of image steganography. The experiments involve tens of millions of repeated steganalytic attacks and show that pooled steganalysis can give very reliable detection of even tiny proportionate payloads.

Wet paper codes with improved embedding efficiency

Abstract: Construction of steganographic schemes in which the sender and the receiver do not share the knowledge about the location of embedding changes requires wet paper codes. Steganography with non-shared selection channels empowers the sender as now he is able to embed secret data by utilizing arbitrary side information, including a high-resolution version of the cover object (perturbed quantization steganography), local properties of the cover (adaptive steganography), and even pure randomness, e.g., coin flipping, for public key steganography. In this paper, we propose a new approach to wet paper codes using random linear codes of small codimension that at the same time improves the embedding efficiency-the number of message bits embedded per embedding change. We describe a practical algorithm, test its performance experimentally, and compare the results to theoretically achievable bounds. We point out an interesting ripple phenomenon that should be taken into account by practitioners. The proposed coding method can be modularly combined with most steganographic schemes to allow them to use non-shared selection channels and, at the same time, improve their security by decreasing the number of embedding changes.

Analysis of Current Steganography Tools: Classifications & Features

Abstract: The technology of information hiding has developed rapidly in recent years. The number of steganography software has reached more than 200 at present. This paper focuses on the steganography tools? algorithms. Based on the analyses of these algorithms, we partition these tools into five categories: (1). Spatial domain based steganography tools; (2). Transform domain based steganography tools; (3). Document based steganography tools; (4) File structure based steganography tools; (5). Other categories, e.g. video compress encoding and spread spectrum technique based. Moreover, we give an in-depth analysis of the feature of each category.

Cover Selection for Steganographic Embedding

Abstract: The primary goal of image steganography techniques has been to maximize embedding rate while minimizing the detectability of the resulting stego images against steganalysis techniques. However, one particular advantage of steganography, as opposed to other information hiding techniques, is that the embedder has the freedom to choose a cover image that results in the least detectable stego image. This resource has largely remained unexploited in the proposed embedding techniques. In this paper, we study the problem of cover selection by investigating three scenarios in which the embedder has either no knowledge, partial knowledge, or full knowledge of the steganalysis technique. For example, we illustrate through experiments how simple statistical measures could help embedder minimize detectability, at times by 65%, in the partial knowledge case.

High-payload image steganography using two-way block matching

Abstract: This letter presents a novel image steganography method that utilizes a two-way block-matching procedure to search for the highest similarity block for each block of the important image. The bases and indexes obtained together with some not-well-matched blocks are recorded in the least significant bits of the cover image using a hop scheme. The method exhibits a high data payload, which reduces the storage and transmission-time requirements and also provides a method that prevents an observer from selectively blocking the transmission of the important image.

A New Genetic Algorithm Approach for Secure JPEG Steganography

Abstract: Steganography is the act of hiding a message inside another message in such a way that can only be detected by its intended recipient. Naturally, there are security agents who would like to fight these data hiding systems by steganalysis, i.e. discovering covered messages and rendering them useless. There is currently no steganography system which can resist all steganalysis attacks. In this paper we propose a novel GA evolutionary process to make a secure steganographic encoding on JPEG images. Our steganography step is based on OutGuess which is proved to be the least vulnerable steganographic system. A combination of OutGuess steganalysis approach and Maximum Absolute Difference (MAD) for the image quality are used as the GA fitness function. The model presented here is based on JPEG images; however, the idea can potentially be used in other multimedia steganography as well.

WLAN steganography: a first practical review

Abstract: Two different approaches for constructing a steganographic channel in an IEEE 802.11 (WLAN) network are introduced in this paper. First test results on the reliability, undetectability and capacity of a prototypical implementation of both approaches are described and discussed.

Multi bit plane image steganography

Abstract: This paper addresses a novel steganography method for images. Most statistical steganalysis algorithms are strong to defeat previous steganography algorithms. RS steganalysis and pixel difference histogram analysis are two well-known statistical steganalysis algorithms which detect non-random changes caused by embedding a secret message into cover image. In this paper, we first explain how two steganalysis algorithms exploit the effect of the non-random changes and then propose a new steganography method that avoids the non-random changes to evade statistical analysis methods. For this purpose, we adjust the embedding process to be more adaptive to cover image by considering embedding in Gray code bit planes, not natural binary bit planes, of cover images, and two parameters: (1) similarity threshold for selecting non-flat area in lower bit planes, and (2) size of flat blocks n×n in embedding bit planes. Experimental results show that the secret messages embedded by our method are undetectable under RS steganalysis and pixel difference histogram analysis.

Dynamical running coding in digital steganography

Abstract: A novel coding method for digital steganography is described, in which the amount of bit alterations introduced into a cover medium is significantly reduced, leading to less distortion and enhanced security against steganalysis. Unlike other block-based stego-coding approaches, the proposed method works in a running manner. In this way, each secret bit is represented by a series of consecutive cover bits, and flipping of one cover bit can be used to insert several secret bits. Theoretical analysis shows that, by reducing host alterations and inducing less distortion, the running coding has advantages over a previous technique.

Discovering Hidden Evidence

Abstract: Over the past decade, the advancement of a myriad of methods, techniques and technologies to conceal digital evidence and covertly communicate have increased at an alarming rate. In addition, new information suggests that the download of an arsenal of software tools that perform these functions further suggests greater interest and usage of such cyber weapons. Steganography is here, and combined with the Internet and peer to peer networking, it provides criminals, gangs and terrorists with a viable and covert method of communication with guaranteed evidence concealment. This article discusses, in detail, the state-of-the-art in the most advanced Steganography tools and techniques available to perpetrators today. We include statistics regarding Steganography expansion, growth and usage, and discuss the specific digital forensic artifacts that help lead to discovery and extraction. All of the image files used to develop this article are available for free download from the publisher's online editio...

A New Method for Real-Time Steganography

Abstract: The hidden, real-time sending and display of information, esp. in public places, has since long received attention and faced many challenges. Therefore, different methods have been proposed so far for hiding information in different cover media. In this paper I propose a new method for the real-time hiding of information without need to any storage cover media. This method is based on the real-time hiding of information in output screens of the instrument (such as screens shown by the monitor). This method of steganography is very similar to the two discussions of image steganography and video steganography. The idea suggested in this paper was simulated on a PC computer by using the Pascal programming language

Content-aware steganography: about lazy prisoners and narrow-minded wardens

Abstract: We introduce content-aware steganography as a new paradigm. As opposed to classic steganographic algorithms that only embed information in the syntactic representation of a datagram, content-aware steganography embeds secrets in the semantic interpretation which a human assigns to a datagram. In this paper, we outline two constructions for content-aware stegosystems, which employ, as a new kind of security primitive, problems that are easy for humans to solve, but difficult to automate. Such problems have been successfully used in the past to construct Human Interactive Proofs (HIPs), protocols capable of automatically distinguishing whether a communication partner is a human or a machine.

Determining Achievable Rates for Secure, Zero Divergence, Steganography

Abstract: In steganography (the hiding of data into innocuous covers for secret communication) it is difficult to estimate how much data can be hidden while still remaining undetectable. To measure the inherent detectability of steganography, Cachin [1] suggested the ?-secure measure, where ? is the Kullback Leibler (K-L) divergence between the cover distribution and the distribution after hiding. At zero divergence, an optimal statistical detector can do no better than guessing; the data is undetectable. The hider's key question then is, what hiding rate can be used while maintaining zero divergence? Though work has been done on the theoretical capacity of steganography, it is often difficult to use these results in practice. We therefore examine the limits of a practical scheme known to allow embedding with zero-divergence. This scheme is independent of the embedding algorithm and therefore can be generically applied to find an achievable secure hiding rate for arbitrary cover distributions.

A Steganalysis Method Based on the Distribution of First Letters of Words

Abstract: Semantic steganograhpy is a method using texts to hide secret messages, which embeds messages into texts at the level of linguistic understanding. This paper studies the semantic steganography method, and analyzes the statistical features to search the differences between stego-texts and natural texts by modeling the latter. And a steganalysis method is designed based on the distribution of first letters of words according to the differences. The method is easy to achieve, and experiments prove the efficiency and reliability of the method.

A Dynamic Compensation LSB Steganography Resisting RS Steganalysis

Abstract: Through dynamic compensation of pixel values of the LSB embedded image, this paper presents a novel LSB steganography method against RS, a powerful LSB steganalysis technique proposed by Fridrich with high precision. Firstly, this method embeds message in the LSB plane of the carrier image randomly, then make a dynamic compensation on the steg-image. Theoretic analysis and experimental results show that even the embedding rate is near 100% in this steg-image, such dynamic compensation can make RS steganalysis get a very small estimate value close to 0, which will cause an incorrect judgement. Moreover, the selection parameters of the compensation can be used as a part of the steganography system key to improve the steganography system's security, and the experimental results also indicate that this method is efficient to defeat some other LSB steganalysis methods

A Filtering Based Approach to Adaptive Steganography

Abstract: An ideal steganographic technique embeds message information into a carrier image with virtually imperceptible modification of the image Adaptive steganography comes closer to this ideal since it exploits the natural variations in the pixel intensities of a cover image to hide the secret message The objective of adaptive steganographic methods in the literature is to embed a message, such that the obtained steganographic images appear unmodified These approaches are limited due to use of local image information and the lack of parametric control of embedding capacity In this paper a new method of adaptive steganography is proposed, that uses both global and local image features The novel approach allows for a high embedding capacity and enhanced security A detailed algorithm is presented along with results of its application on some sample images A comparison between the features of existing adaptive steganographic methods and the new method are also presented

Collage Steganography

Abstract: Establishing hidden communication is an important subject of discussion that has gained increasing importance nowadays with the development of the Internet. One of the methods introduced for establishing hidden communication is steganography. Methods of steganography have been mostly applied on images while the major characteristic of these methods is the change in the structure and features of the images so as not to be identifiable by human users. However, on the other hand, many methods have been proposed for breaking and extracting information (steganalysis) for these methods. This paper presents a method for hiding information in images by changing the appearance of the picture instead of changing its features. In this method, images of a number of relevant objects are put on a scene together in a way that is not noticeable. Then, by changing the place and type of each object, information is hidden in the image because the place and type of each object indicates a special figure and, by putting the digits figures together, the information in question is hidden in the picture. Considering that in this method information has been hidden in the appearance of the picture, then by using the present methods of identification of stegano images one cannot identify the steganography images in this method or extract data from them. The proposed method has been implemented by using the Java programming language.

Steganography obliterator: an attack on the least significant bits

Abstract: Steganography is the art of concealing messages through hidden data that is embedded in a carrier medium. Current steganalysis practices focus on detecting and recovering these pieces of hidden data. This paper focuses on instances when neither detecting nor recovering data is desirable, but on proactively cleansing the cover media from possible steganographic data. To support this need, a proof-of-concept steganography obliterator is designed and implemented to partially or completely remove the hidden message from possible media carriers such as image, video, and audio files.

A Research on Steganography Method Based on Error-Correcting Codes

Abstract: With the encoding redundancy of Error-Correcting codes a new steganography method is proposed. A mapping code between secret information and codeword error map is built. By modifying the part of the codeword of the error-correcting codes according to the error map secret information is embedded. Theoretical analysis and experimental results show that this method has better security.

Application of T-Code, Turbo Codes and Pseudo-Random Sequence for Steganography

Abstract: In this study, we propose new technique that will address the problem of robustness and data safety in steganography. The steganography consists of techniques to allow the communication between two persons, hiding not only the contents but also the very existence of the communication in the eyes of any observer. T-Codes used with Turbo Codes generates cryptic and error-coded data stream, which is hidden in the stego-object using Pseudo-Random sequence. This technique makes our processed data stream non-vulnerable to the attack of an active intruder, or due to noise in the transmission link.

Integrity Verification of Secret Information in Image Steganography

Abstract: We propose a new image steganogrphy method to verify whether the secret information had been deleted, forged or changed by attackers. The proposed method hides secret information into spatial domain of digital image. In this paper, we can verify the integrity from extracted secret information using the AC coefficients of the discrete cosine transform (DCT) domain. Keywords— Steganography, DCT, Integrity Verification

A Steganalysis Method Based on the Distribution of Characters

Abstract: Semantic steganograhpy is a method using texts to hiding secret information, which embeds message into texts at the level of linguistic understanding. This paper studies the semantic steganography method, and analyzes the statistical features to search the differences between stego-texts and natural texts by modeling the latter. And a steganalysis method is designed based on the distribution of characters according to the differences. The method is easy to achieve, and experiments prove the efficiency and reliability of the method

Real-time steganography in compressed video

Abstract: An adaptive and large capacity steganography method applicable to compressed video is proposed. Unlike still images, video steganography technology must meet the real-time requirement. In this work, embedding and detection are both done entirely in the variable length code (VLC) domain with no need for full or even partial decompression. Also, embedding is guided by several so-called A/S trees adaptively. All of the A/S trees are generated from the main VLC table given in the ISO/IEC13818-2:1995 standard. Experimental results verify the excellent performance of the proposed scheme.

Undercover communication using image and text as disguise and countermeasures

Abstract: A brief survey of some representative techniques of steganography and steganalysis is presented. Various methods developed in the authors’ laboratory are introduced, including symmetric LSB embedding, secure steganography in JPEG, palette, and uncompressed color images, histogram-based analysis and least histogram abnormality steganography, multiple-base notational system based embedding, stego-encoding integrated with error correction, etc. Some of the proposed approaches provide overall improvement, while others offer alternatives to existing techniques with advantage in certain aspects. Data hiding in text using the typesetting tool TeX is also introduced, with a brief description of a recently developed technique. Current research topics and the future plan are outlined. The discussion is focused mainly on steganography/steganalysis in still images.

Steganalysis in the presence of weak cryptography and encoding

Abstract: Steganography is often combined with cryptographic mechanisms. This enhances steganography by valuable properties that are originally left to cryptographic systems. However, new problems for cryptographic mechanisms arise from the context of steganography. There are two sorts of steganographic tools: commercial tools with insecure or badly implemented cryptography and academic proof-of-concepts that abstain from the actual implementation of the cryptographic part. Comparably to cryptography, steganography evolves in an iterative process of designing and breaking new methods. In this paper we examine the encoding properties and cryptographic functionality of steganographic tools to enable the detection of embedded information in steganograms even if the embedding part was otherwise secure.

Steganalysis in the presence of weak cryptography and encoding

Abstract: Steganography is often combined with cryptographic mechanisms. This enhances steganography by valuable properties that are originally left to cryptographic systems. However, new problems for cryptographic mechanisms arise from the context of steganography. There are two sorts of steganographic tools: commercial tools with insecure or badly implemented cryptography and academic proof-of-concepts that abstain from the actual implementation of the cryptographic part. Comparably to cryptography, steganography evolves in an iterative process of designing and breaking new methods. In this paper we examine the encoding properties and cryptographic functionality of steganographic tools to enable the detection of embedded information in steganograms even if the embedding part was otherwise secure.