Martin Broda

Image steganography based on combination of YC b C r color model and DWT

Steganography is the process of implanting secret message in a cover data without causing degradation neither to the cover information nor to the secret message implanted in the cover data. Most of the steganographic techniques are applied on images, texts, and protocols. In this paper a novel algorithm of image steganography is proposed to implant a secret text message into a cover image using YCbCr color space model and 2D Haar Discrete Wavelet Transform. In this proposed technique, input text in ASCII code is encrypted by AES what ensures, that the relative letter frequency of a plain text secret message will be disturbed. Proposed technique also solves conversion between color space models RGB and YCbCr in spite of modification in component Cb by the secret message. This step allows extracting of secret message without errors what is a very important characteristic, because change of only one bit causes extracting of different character. Performance of the proposed algorithm has been gauged by the peak signal to noise ratio (PSNR) and mean square error (MSE) for the stego image.

Image steganography with using QR code and cryptography

This paper is focused on proposal of image steganographic method that is able to embedding of encoded secret message using Quick Response Code (QR) code into image data. Discrete Wavelet Transformation (DWT) domain is used for the embedding of QR code, while embedding process is additionally protected by Advanced Encryption Standard (AES) cipher algorithm. In addition, typical characteristics of QR code was broken using the encryption, therefore it makes the method more secure. The aim of this paper is design of image steganographic method with high secure level and high non-perceptibility level. The relation between security and capacity of the method was improved by special compression of QR code before the embedding process. Efficiency of the proposed method was measured by Peak Signal-to-Noise Ratio (PSNR) and achieved results were compared with other steganographic tools.

A novel approach for image steganalysis

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.

Universal statistical steganalytic method

Abstract Novel image steganalytic method used to detection of secret message in static images is introduced in this paper. This method is based on statistical steganalysis (SS), where statistical vector is composed by 285 statistical features (parameters) extracted from DCT (Discrete Cosine Transformation) domain and 46 features extracted mainly from DWT (Discrete Wavelet Transformation) domain. Classification process was realized by Ensemble classifier that was helpful in reduction of computational and time complexity. Proposed steganalytic method was verified by detection of popular image steganographic methods. Novel method was also compared with existing steganalytic methods by overall detection accuracy of a secret message.

A novel block-based data hiding scheme in SVD-DCT composite domain

This paper presents a robust block-based watermarking scheme for multimedia copyright protection. In this work, we used benefits of domain combination of Singular Value Decomposition (SVD) and Discrete Cosine Transformation (DCT). Our aim was to utilize the favorable properties of both transformations to design of a unique and useful transformation standard algorithm for embedding watermarks into cover data. The proposed watermarking scheme is verified from the point of view of imperceptibility expressed by objective quality measure PSNR (Peak Signal-to-Noise Ratio) and robustness to different types of removal (JPEG compression, Gaussian filtering, Sharpening) and geometric attacks (Scaling and Rotating).

Robust spread spectrum watermarking system in video

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.