Information Hiding
and its Applications
Steganography and Watermarking
A detailed look at Steganography
   ◦ Text Steganography
   ◦ Hypertext Steganography
   ◦ Audio Steganography
   ◦ Image Steganography
   ◦ Steganography in Open System
Image Steganography Techniques
   ◦ Spatial Domain LSB Insertion
   ◦ Masking and Filtering
   ◦ DCT-based Steganography
   ◦ Wavelet-based Steganography
How to Detect Steganography
   ◦ Blind Detection
   ◦ Analytical Detection

• Overview Papers and Articles about Steganography and Steganalysis.
• Articles and Papers about Image-based Steganography Methods.
• Theses about Steganography and Steganalysis.
• Articles and Papers about Steganalysis.

• F5 - A Steganographic Algorithm, Andreas Westfeld, 2001.
• OutGuess: Defending Against Statistical Steganalysis, Niels Provos.
• Model-Based Steganography, Phil Sallee, 2004.
• A Secure Steganographic Method on Wavelet Domain of Palette-Based Images,
  by Wei Ding, Xiang-Wei Kong, Xin-Gang You, and Zi-Ren Wang, 2004.
• An Adaptive DCT-Based Mod-4 Steganographic Method, Xiaojun Qi, KokSheik Wong, 2005.
• Hiding Data in Binary Images, Chin-Chen Chang, Chun-Sen Tseng, Chia-Chen Lin, 2005.
• Quantization-Based Image Steganography without Data Hiding Position Memorization, Yusuke SEKI, Hiroyuki KOBAYASHI,
  Masaaki FUJIYOSHI, Hitoshi KIYA, 2005.
• A DCT-based Mod4 steganographic method, KokSheik Wong, Xiaojun Qi, Kiyoshi Tanaka, 2007.
• PM1 steganography in JPEG images using genetic algorithm, Lifang Yu, Yao Zhao, Rongrong Ni, Zhenfeng Zhu, 2008.

F5 - A Steganographic Algorithm,
High Capacity Despite Better Steganalysis

By Andreas Westfeld , Technische Universität Dresden, Institute for System Architecture, 2001.

ABSTRACT:

Many steganographic systems are weak against visual and statistical attacks. Systems without these weaknesses offer only a relatively small capacity for steganographic messages. The newly developed algorithm F5 withstands visual and statistical attacks, yet it still offers a large steganographic capacity. F5 implements matrix encoding to improve the efficiency of embedding. Thus it reduces the number of necessary changes. F5 employs permutative straddling to uniformly spread out the changes over the whole steganogram.

Defending Against Statistical Steganalysis

By Niels Provos, Center for Information Technology Integration, University of Michigan.

ABSTRACT:

The main purpose of steganography is to hide the occurrence of communication. While most methods in use today are invisible to an observer’s senses, mathematical analysis may reveal statistical anomalies in the stego medium. These discrepancies expose the fact that hidden communication is happening. This paper presents improved methods for information hiding. One method uses probabilistic embedding to minimize modifications to the cover medium. Another method employs error-correcting codes, which allow the embedding process to choose which bits to modify in a way that decreases the likelihood of being detected. In addition, we can hide multiple data sets in the same cover medium to provide plausible deniability. To prevent detection by statistical tests, we preserve the statistical properties of the cover medium. After applying a correcting transform to an image, statistical steganalysis is no longer able to detect the presence of steganography. We present an a priori estimate to determine the amount of data that can be hidden in the image while still being able to maintain frequency count based statistics. This way, we can quickly choose an image in which a message of a given size can be hidden safely. To evaluate the effectiveness of our approach, we present statistical tests for the JPEG image format and explain how our new method defeats them.

Model-Based Steganography

By Phil Sallee, University of California, 2004.

ABSTRACT:

This paper presents an information-theoretic method for performing steganography and steganalysis using a statistical model of the cover medium. The methodology is general, and can be applied to virtually any type of media. It provides answers for some fundamental questions which have not been fully addressed by previous steganographic methods, such as how large a message can be hidden without risking detection by certain statistical methods, and how to achieve this maximum capacity. Current steganographic methods have been shown to be insecure against fairly simple statistical attacks. Using the model-based methodology, an example steganography method is proposed for JPEG images which achieves a higher embedding efficiency and message capacity than previous methods while remaining secure against first order statistical attacks.

A Secure Steganographic Method on Wavelet Domain of Palette-Based Images

By Wei Ding, Xiang-Wei Kong, Xin-Gang You, and Zi-Ren Wang, School of Electronic and Information Engineering, Dalian University of Technology, China.

ABSTRACT:

This article presents a novel secure steganographic method on wavelet domain of GIF images. Secret information is usually embedded in palettes or indices of GIF images directly by formerly presented steganographic methods. These methods may introduce visible noise and detectable changes of parameters in images. The new method based on integer wavelet transform dispels noise introduced by data-hidding into adjacent pixels. Matrix encoding is also applied in embedding. Both scattering noise and matrix encoding improve the quality of the stego-images and the security of secret communication. Experimental results show the fine security of the proposed method in resisting attacks by χ2 detecting method and Fridrich’s detecting method.

An Adaptive DCT-Based MOD-4 Steganographic Method

By Xiaojun Qi and KokSheik Wong, Computer Science Department, Utah State University.

ABSTRACT:

This paper presents a novel Mod-4 steganographic method in discrete cosine transform (DCT) domain. A group of 2£2 quantized DCT coef cients (GQC) is selected as the valid embedding area if more than two DCT coef cients are outside the interval of [¡1; 1]. The modulo 4 arithmetic operation is further applied to all the valid GQCs to embed a pair of binary bits using the shortest-route modi cation scheme. Each secret message is also encrypted to provide the system with more security. The proposed system has been extensively tested on a variety of images with different textures. Experimental results demonstrate that our system successfully preserves the quality of the images and stays undetected by the well- known steganalysis methods.

Hiding Data in Binary Images

By Chin-Chen Chang, Chun-Sen Tseng, Chia-Chen Lin, 2005.

ABSTRACT:

This paper presents a novel scheme for embedding secret data into a binary image. In Tseng et al.’s scheme, a random binary matrix and a weight matrix are used as the secret keys to protect the secret information. In our scheme, we use a serial number matrix instead of a random binary matrix to reduce computation cost and to provide higher security protection on hidden secret data than Tseng et al. do. Given a cover image divided into blocks of m×n pixels each, our new scheme can hide e ⎣log ( 1)⎦ 2 mn + bits of hidden data with one modified bit at most in each block in the cover image. In addition, the hiding capacity of our new scheme offers is as large as that of Tseng et al.’s scheme, but we support higher stego-image quality than Tseng et al.’s scheme does.

Quantization-Based Image Steganography without Data Hiding Position Memorization

By Yusuke SEKI, Hiroyuki KOBAYASHI, Masaaki FUJIYOSHI, Hitoshi KIYA, 2005.

ABSTRACT:

This paper proposes a quantization-based steganography method of extracting hidden data without any reference images or memorization of positions, into which data are embedded. Since the proposed method offers the user the flexibility of choosing data hiding positions, it enables the user to select positions for embedding data on an individual image basis and/or the basis of the coding scheme being applied to the images. Simulation results show the effectiveness of this method.

A DCT-based Mod4 steganographic Method

By KokSheik Wong, Xiaojun Qi, Kiyoshi Tanaka, 2007.

ABSTRACT:

This paper presents a novel Mod4 steganographic method in discrete cosine transform (DCT) domain. Mod4 is a blind steganographic method. A group of 2 2 spatially adjacent quantized DCT coefficients (GQC) is selected as the valid message carrier. The modulus 4 arithmetic operation is then applied to the valid GQC to embed a pair of bits. When modification is required for data embedding, the shortest route modification scheme is applied to reduce distortion as compared to the ordinary direct modification scheme. Mod4 is capable in embedding information into both uncompressed and JPEG-compressed image. To compare Mod4 with other existing methods, carrier capacity, stego image quality, and results of blind steganalysis for 500 various images are shown. Visual comparison of three additional metrics is also presented to show the relative performance of Mod4 among other existing methods.

PM1 Steganography in JPEG Images Using Genetic Algorithm

By Lifang Yu, Yao Zhao, Rongrong Ni, Zhenfeng Zhu, 2008.

ABSTRACT:

Plus minus 1 (PM1) is an improved method to least significant bits (LSB)-based steganography techniques, which not only foils typical attacks against LSB-based techniques, but also provides high capacity. But how to apply it to JPEG images does not appear in literatures. In this paper, PM1 steganography in JPEG images using genetic algorithm (GA) is proposed, in which the GA is used to optimize the performance, such as minimizing blockiness. Theoretical analysis to the histogram characteristics after steganography is discussed in details, which proves that PM1 used in JPEG images preserves the first-order statistical properties. Experiments show that the proposed method outperforms the other methods in terms of capacity and security.