Steganography is the science of hiding secret information in another unsuspicious data. Generally, a steganographic secret message could be a widely useful multimedia: as a picture, an audio file, a video file or a message in clear text - the covertext. The most recent steganography techniques tend to hide a secret message in digital images. We propose and analyze experimentally a blind steganography method based on specific attributes of two dimensional discrete wavelet transform set by Haar mother wavelet. The blind steganography methods do not require an original image in the process of extraction what helps to keep a secret communication undetected to third party user or steganalysis tools. The secret message is encoded by Huffman code in order to achieve a better imperceptibility result. Moreover, this modification also increases the security of the hidden communication.

In this paper we propose robust watermarking schema for video files based on spread spectrum theory. The main concept relies on utilization of time as temporal dimension for spreading of watermark bits that are assigned to video frames. The second level spreading that is impartial to first level, uses different set of PN sequences within the video frames what allows to utilize multiple watermarking methods designed for still images simultaneously. Two dimensional spread spectrum watermarking framework allows acquiring a high level of robustness with desired imperceptibility of hidden watermark. Two independent embedding methods LSB and DCT were tested during embedding as representative techniques of different embedding domain. The presented results show that proposed watermarking schema is able to withstand intentional attacks. The proposed system is robust and adaptive to recent and newly developed embedding technique, which could provide a requisite of robustness and protection against copyright infringement.

The Elliptic Curve Cryptosystem is an emerging alternative for traditional Public-Key Cryptosystem like RSA, DSA and DH. It provides the highest strength-per-bit of any cryptosystem known today with smaller key sizes resulting in faster computations, lower power consumption and memory. It also provides a methodology for obtaining high-speed, efficient and scalable implementation of protocols for authentication. The objective is to give the reader an overview on efficient addition and doubling formulas of Edwards curves together with analysis and effective parallel decomposition of these formulas. Practical analysis is provided with implementation consideration.

In the paper we introduce a new universal steg- analytic method in JPEG file format that is detecting well- known and also newly developed steganographic methods. The steganalytic model is trained by MHF-DZ stegano- graphic algorithm previously designed by the same authors. The calibration technique with the Feature Based Steganalysis (FBS) was employed in order to identify sta- tistical changes caused by embedding a secret data into original image. The steganalyzer concept utilizes Support Vector Machine (SVM) classification for training a model that is later used by the same steganalyzer in order to identify between a clean (cover) and steganographic image. The aim of the paper was to analyze the variety in accuracy of detection results (ACR) while detecting testing steganographic algorithms as F5, Outguess, Model Based Steganography without deblocking, JP Hide&Seek which represent the generally used steganographic tools. The comparison of four feature vectors with different lengths FBS (22), FBS (66) FBS(274) and FBS(285) shows prom- ising results of the proposed universal steganalytic method comparing to binary methods.

Since JPEG images have been widely used in our daily life, the steganalysis for JPEG images becomes very important and significant. The Article addresses steganalysis in static images based on DCT transformed region, able to recognize the most popular steganography algorithms occurring on the Internet. We propose a new steganalysis method, where statistical properties of the image are explored, regardless the embedding procedure employed. The feature set used for classification of images consists of 285 statistical features. Experimental results show that in comparing with the universal steganalysis method for JPEG stego images, our method improves detection of widely used steganographic method in detection process, which provides observable differences in investigation performance.

This paper is focused on comparison of two steganalytic methods that are able to detect embedding of secret message using popular and novel steganographic algorithms in JPEG images. First one is based on binary similarity measures and second method exploits 66 or 274 statistical features in transform domain from cover and stego images. The tested universal model was trained using novel steganographic method previously proposed by the same authors. Subsequently, the obtained statistical parameters from cover and stego images are used for training of model that is applied on detection of secret message in testing phase. The aim of this paper was to examine the accuracy detection (ACR) of these novel universal steganalytic models for popular steganographic tools in static images and also to compare time consumption in process of extraction parameters and training of model.

In this paper we propose two dimensional spread spectrum watermarking framework based on Direct Spread Spectrum theory using PN sequences. The presenting schema allows acquiring a high level of robustness with desired imperceptibility. The aim of this paper was to present robust and adaptive watermarking system for multimedia protection, where hidden watermark provides a desired requisition against copyright infringement. Media content delivery system incorporated by cryptographic public-key was proposed in the paper as part of. The framework concept was applied to digital video content to simulate 2D-level spreading technique of hidden watermark data.

This paper presents results of multi-classification and cross-validation of tested steganalysis method in static images in JPEG format. Steganalysis methods are used for revealing a secret communication conducted by different steganographic tools. The steganalysis algorithm analyzes changes in statistical parameters of the images using Feature Based Steganalysis. The multi-classification is ability of proposed system to identify an applied steganography methods and cross-validation is defined as steganalytic model's detection efficiency of steganography methods that were not used in training phase of the model. Testing was performed for different length of statistical features' vector and for different size of embedded secret message. The results are also contributing in design of blind steganography system to detect a new steganography tools.

We propose and analyze experimentally a blind steganography method based on specific attributes of two dimensional discrete wavelet transform set by Haar mother wavelet. Steganography is the science that deals with hiding a secret message in unsuspicious cover media. The most recent steganographic techniques tend to hide a secret message in digital images. The blind steganography methods do not require an original image in the process of extraction what helps to keep a secret communication undetected to third party user or steganalysis tools. The secret message is encoded by Huffman code in order to achieve a better imperceptibility result. Moreover, this modification also increases the security of the hidden communication.

The objective of this paper is performance testing of Feature-based Steganalysis methods for detection of steganography tools that are used for hiding a secret message in still images. Many of those tools, which can be used publicly, cause statistical changes in original images during embedding process. The features represent those statistically calculated changes, where feature extraction in this paper was applied in spatial domain and also directly in transformation domain of DCT in JPEG files what helps to obtained relevant statistical data. The results of this paper identify the selection of statistical feature vector that is used during training phase of classifier in order to distinguish between cover and stego image. The reliable detection of selected steganography methods were presented in relation to length of feature vector. Moreover, contribution to design of blind steganalysis system was proposed for the purpose of unveiling a secret communication via completely new steganography methods.

In this paper, we present a novel JPEG steganography method with histogram preserving scheme. The embedding is performed in transformation domain of DCT in JPEG file by modification of selected DCT transform coefficients according to modulo function, which allows to extract the secret message without cover-image being present at the receiver side what gives a predisposition of blind steganography systems. Histogram analysis is deployed to create secure steganography system against histogram attacks. Moreover, AES 128-bit cipher is applied to a secret message in order to increase the security level of steganography system as well as to acquire desired after-embedding histogram characteristics of DCT coefficients.

In this paper, we present a novel steganographic method for embedding of a secret data in still grayscale JPEG image. In order to provide large capacity of proposed method while maintaining good visual quality of stego-image, the embedding process is performed in quantized transform coefficients of Discrete Cosine transform (DCT) by modifying coefficients according to modulo function, what gives to the steganography system blind extraction predisposition. After-embedding histograms of proposed Modulo Histogram Fitting (MHF) method is analysed to secure steganography system against steganalysis attacks. In addition, AES ciphering was implemented to increase security and improve histogram after-embedding characteristics of proposed steganography system as experimental results show.

In this paper, we present a novel steganographic method for embedding of secret data in still grayscale JPEG image. The embedding is performed in DCT domain in JPEG file. Hiding a secret data relies in change of selected quantized DCT transform coefficients according to modulo function, which allows to extract the secret message without cover-image being present what gives predisposition of blind steganography systems. Histogram analysis is deployed to create secure steganography system against histogram attacks. Moreover, prior embedding, a secret message is encrypted by AES 128-bit cipher to increase security level of steganography system as well as to acquire desired after-embedding histogram characteristics of DCT coefficients.

In this paper, we present a novel blind steganographic method for embedding the secret data in still grayscale image. In order to provide large capacity of the secret data while maintaining good visual quality of stego image, the embedding process is performed in transform domain of Discrete Wavelet transform (DWT) by modifying of the detail transform coefficients in an appropriate manner. In addition, the proposed method does not require original image for successful extraction of the secret information. The experimental results show that the proposed method provides good capacity and excellent image quality.

In this paper, we present a novel steganographic method for embedding of secret data in still grayscale image. In order to provide large capacity of the secret data while maintaining good visual quality of stego-image, the embedding process is performed in transform domain of Discrete Wavelet transform (DWT) by modifying of transform coefficients in an appropriate manner. In addition, the proposed method do not require original image for successful extraction of the secret information. The experimental results show that the proposed method provides good capacity and excellent image quality.

In last decade the information communication is marked by countless restrictions of state authorities to monitor and restrain communication of the individuals or groups. Due to retention of privacy protection there are naturally intentions to protect and hide this inapproachable type of communication. However, those intention could have other than illegal notion i. e. bank-houses and business related institutions trying to hide their communication by reason of the security related issues. The steganography as art of science, which is dedicated to the methods of hiding secret communication against a background of the harmless - cover communication. This paper deals about the steganography and also emerging problems of hidden communication in the cover information media as imperceptibility and capacity of designed steganographic channel, and after all finding suitable embedding techniques to meet conditions claimed upon steganography.

In this paper, we present a novel method of steganography system based on CDMA (Code Division Multiple Access) approach having regard to perceptibility of stego-image. Also additional extraction algorithms were designed due to enhancing of secret message decomposition. As it will be shown later, aptly imposed features of CDMA techniques are in consonance with imperatives claimed upon steganography systems.

In this paper, we present a novel method called Code Book in steganography system based on CDMA (Code Division Multiple Access) techniques having regard to perceptibility of stego-image. These techniques and their variations are widely used in radio telecommunication systems. As it will be shown later, aptly imposed features of CDMA techniques are in consonance with imperatives claimed upon steganography systems.