Tayana Morkel

Bio: Tayana Morkel is an academic researcher from University of Pretoria. The author has contributed to research in topics: Steganography tools & Steganography. The author has an hindex of 3, co-authored 5 publications receiving 530 citations.

An overview of image steganography.

Abstract: Steganography is the art of hiding the fact that communication is taking place, by hiding information in other information. Many different carrier file formats can be used, but digital images are the most popular because of their frequency on the Internet. For hiding secret information in images, there exists a large variety of steganographic techniques some are more complex than others and all of them have respective strong and weak points. Different applications have different requirements of the steganography technique used. For example, some applications may require absolute invisibility of the secret information, while others require a larger secret message to be hidden. This paper intends to give an overview of image steganography, its uses and techniques. It also attempts to identify the requirements of a good steganographic algorithm and briefly reflects on which steganographic techniques are more suitable for which applications.

Using image steganography for decryptor distribution

Abstract: When communicating secret information there is more than one route to follow to ensure the confidentiality of the message being transmitted Encryption might be an obvious choice; however there are limitations and disadvantages to using encryption An alternative approach is steganography, which is a technology for hiding information in other information Combining the two disciplines may provide better security but more overhead, since the receiver must now have knowledge not only of how the information was encrypted, but also of how it was hidden, in order to retrieve the message This paper proposes a system where image steganography is combined with encryption by hiding not only a message inside an image, but also the means to extract and decrypt the message An executable program is hidden inside the image that functions as a decryptor, enabling the receiver to be oblivious to the encryption algorithm used.

The OSN-Tagging scheme: Recoverable steganography for online social networks

Abstract: Online social networks (OSNs) offer the functionality of sharing information and images between users. The sharing of specifically images, offers a promising covert channel for secure and private communication by hiding information in images using steganography. However, many known steganography algorithms are not suitable for OSNs since the image processing that is performed when uploading an image modifies the image in such a way that the embedded information becomes irrecoverable. This paper proposes a steganography scheme that uses a variation of the Tagging watermarking algorithm (not to be confused with the Facebook concept of tagging) to embed a message in an image that can survive the image processing done by OSNs. The proposed OSN-Tagging scheme adjusts the brightness levels of certain areas of an image, thereby representing a message. Experimental results show that the tags and message embedded with the OSN-Tagging scheme can successfully be recovered after the image was uploaded to an OSN. Recommendations and considerations are made regarding tag size and brightness adjustment levels based on experimental results.

Self-sanitization of digital images using steganography

Abstract: Sanitization of an image is a process where certain areas of an image are removed to keep the contents safe from unauthorised viewers. Image sanitization is often required by authorities, for example law enforcement or in legal cases, when the image contains sensitive material that should not be shown to the general public. This paper proposes a system for the self-sanitization of a digital image using information hiding, specifically image steganography, techniques to hide part of the image within the image itself. The proposed self-sanitization system allows for the removal of a specific part of the image and then uses Least Significant Bit (LSB) steganography to embed the sanitized part of the image within the rest of the image, making it unnecessary to store the sanitized and unsanitized versions of the image separately. The self-sanitization system includes a method for reducing the size of the embedded information in an attempt to make the information more difficult to detect. Experimental results show that the proposed self-sanitization system is undetectable to visual and statistical analysis techniques.

A new approach for LSB based image steganography using secret key

Abstract: This paper introduces a best approach for Least Significant Bit (LSB) based on image steganography that enhances the existing LSB substitution techniques to improve the security level of hidden information. It is a new approach to substitute LSB of RGB true color image. The new security conception hides secret information within the LSB of image where a secret key encrypts the hidden information to protect it from unauthorized users. In general, in LSB methods, hidden information is stored into a specific position of LSB of image. For this reason, knowing the retrieval methods, anyone can extract the hidden information. In our paper, hidden information is stored into different position of LSB of image depending on the secret key. As a result, it is difficult to extract the hidden information knowing the retrieval methods. We have used the Peak Signal-to-Noise Ratio (PSNR) to measure the quality of the stego images. The value of PSNR gives better result because our proposed method changes very small number of bits of the image. The obtained results show that the proposed method results in LSB based image steganography using secret key which provides good security issue and PSNR value than general LSB based image steganography methods.

A novel image steganography scheme with high embedding capacity and tunable visual image quality based on a genetic algorithm

Abstract: Steganography is knowledge and art of hiding secret data into information which is largely used in information security systems. Various methods have been proposed in the literature which most of them are not capable of both preventing visual degradation and providing a large embedding capacity. In this paper, we propose a tunable visual image quality and data lossless method in spatial domain based on a genetic algorithm (GA). The main idea of the proposed technique is modeling the steganography problem as a search and optimization problem. Experimental results, in comparison with other currently popular steganography techniques, demonstrate that the proposed algorithm not only achieves high embedding capacity but also enhances the PSNR of the stego image.

Image steganography techniques: an overview

Abstract: Steganography - the art and science of hiding information has received much attention in the recent years. It can also be defined as the study of invisible communication that usually involves communication of secret data in an appropriate carrier, e.g., image, audio, video or TCP/IP header file. Many different carrier file formats can be used, but digital images are the most popular because of their frequency on the Internet. The main goal of steganography is to ensure that the transmitted message is completely masked, thereby ensuring that the message is accessible only to the intended receiver and does not attract attention from eavesdroppers and attackers. This paper is an attempt to study the various techniques use in steganography and provide a general overview of different algorithms of image steganography. There exists a large variety of steganography techniques

A steganography embedding method based on edge identification and XOR coding

Abstract: A method for hiding data in the spatial or IWT domains of images is proposed.Design new edge detection method to estimate same edge intensities for both images.XOR operation is used to embed the message and to improve imperceptibility.Proposed method is robust against textural feature steganalysis. In this paper, we present a novel image steganography algorithm that combines the strengths of edge detection and XOR coding, to conceal a secret message either in the spatial domain or an Integer Wavelet Transform (IWT) based transform domain of the cover image. Edge detection enables the identification of sharp edges in the cover image that when embedding in would cause less degradation to the image quality compared to embedding in a pre-specified set of pixels that do not differentiate between sharp and smooth areas. This is motivated by the fact that the human visual system (HVS) is less sensitive to changes in sharp contrast areas compared to uniform areas of the image. The edge detection method presented here is capable of estimating the exact edge intensities for both the cover and stego images (before and after embedding the message), which is essential when extracting the message. The XOR coding, on the other hand, is a simple, yet effective, process that helps in reducing differences between the cover and stego images. In order to embed three secret message bits, the algorithm requires four bits of the cover image, but due to the coding mechanism, no more than two of the four bits will be changed when producing the stego image. The proposed method utilizes the sharpest regions of the image first and then gradually moves to the less sharp regions. Experimental results demonstrate that the proposed method has achieved better imperceptibility results than other popular steganography methods. Furthermore, when applying a textural feature steganalytic algorithm to differentiate between cover and stego images produced using various embedding rates, the proposed method maintained a good level of security compared to other steganography methods.

Visual cryptographic steganography in images

Abstract: In today's information age, information sharing and transfer has increased exponentially. The threat of an intruder accessing secret information has been an ever existing concern for the data communication experts. Cryptography and steganography are the most widely used techniques to overcome this threat. Cryptography involves converting a message text into an unreadable cipher. On the other hand, steganography embeds message into a cover media and hides its existence. Both these techniques provide some security of data neither of them alone is secure enough for sharing information over an unsecure communication channel and are vulnerable to intruder attacks. Although these techniques are often combined together to achieve higher levels of security but still there is a need of a highly secure system to transfer information over any communication media minimizing the threat of intrusion. In this paper we propose an advanced system of encrypting data that combines the features of cryptography, steganography along with multimedia data hiding. This system will be more secure than any other these techniques alone and also as compared to steganography and cryptography combined systems Visual steganography is one of the most secure forms of steganography available today. It is most commonly implemented in image files. However embedding data into image changes its color frequencies in a predictable way. To overcome this predictability, we propose the concept of multiple cryptography where the data will be encrypted into a cipher and the cipher will be hidden into a multimedia image file in encrypted format. We shall use traditional cryptographic techniques to achieve data encryption and visual steganography algorithms will be used to hide the encrypted data.