An Overview of Steganography for the Computer Forensics Examiner (Updated Version, February 2015)

Steganography is the art of covered or hidden writing. The purpose of steganography is covert communication-to hide the existence of a message from a third party. This paper is intended as a high-level technical introduction to steganography for those unfamiliar with the field. It is directed at forensic computer examiners who need a practical understanding of steganography without delving into the mathematics, although references are provided to some of the ongoing research for the person who needs or wants additional detail. Although this paper provides a historical context for steganography, the emphasis is on digital applications, focusing on hiding information in online image or audio files. Examples of software tools that employ steganography to hide data inside of other files as well as software to detect such hidden files will also be presented. An edited version originally published in the July 2004 issues of Forensic Science Communications

Increasing the hiding capacity of low-bit encoding audio steganography using a novel embedding technique

The rapid growth of multimedia transmission leads to lose the owner identity of their products. Therefore, the demand to secure such input is crucial. In this paper, an overview of steganography and its technique applied is introduced. A data hiding within audio signals is studied. LSB technique is used and simulated result is presented. The result is characterized by robustness and high bit rate. It was shown that length of the embedded message (secret message) does not affect the stego signal audibility as long as it does not exceed the length of the original signal

Using Facebook for Image Steganography

Because Facebook is available on hundreds of millions of desktop and mobile computing platforms around the world and because it is available on many different kinds of platforms (from desktops and laptops running Windows, Unix, or OS X to hand held devices running iOS, Android, or Windows Phone), it would seem to be the perfect place to conduct steganography. On Facebook, information hidden in image files will be further obscured within the millions of pictures and other images posted and transmitted daily. Facebook is known to alter and compress uploaded images so they use minimum space and bandwidth when displayed on Facebook pages. The compression process generally disrupts attempts to use Facebook for image steganography. This paper explores a method to minimize the disruption so JPEG images can be used as steganography carriers on Facebook.Comment: 6 pages, 4 figures, 2 tables. Accepted to Fourth International Workshop on Cyber Crime (IWCC 2015), co-located with 10th International Conference on Availability, Reliability and Security (ARES 2015), Toulouse, France, 24-28 August 201

Text hiding in text using invisible character

Steganography can be defined as the art and science of hiding information in the data that could be read by computer. This science cannot recognize stego-cover and the original one whether by eye or by computer when seeing the statistical samples. This paper presents a new method to hide text in text characters. The systematic method uses the structure of invisible character to hide and extract secret texts. The creation of secret message comprises four main stages such using the letter from the original message, selecting the suitable cover text, dividing the cover text into blocks, hiding the secret text using the invisible character and comparing the cover-text and stego-object. This study uses an invisible character (white space) position of in the cover text that used to hide the the secrete sender masseges. The experiments results show that the suggested method presents highly secret due to use the multi-level of complexity to avoid the attackers

A study on the false positive rate of Stegdetect

In this paper we analyse Stegdetect, one of the well-known image steganalysis tools, to study its false positive rate. In doing so, we process more than 40,000 images randomly downloaded from the Internet using Google images, together with 25,000 images from the ASIRRA (Animal Species Image Recognition for Restricting Access) public corpus. The aim of this study is to help digital forensic analysts, aiming to study a large number of image files during an investigation, to better understand the capabilities and the limitations of steganalysis tools like Stegdetect. The results obtained show that the rate of false positives generated by Stegdetect depends highly on the chosen sensitivity value, and it is generally quite high. This should support the forensic expert to have better interpretation in their results, and taking the false positive rates into consideration. Additionally, we have provided a detailed statistical analysis for the obtained results to study the difference in detection between selected groups, close groups and different groups of images. This method can be applied to any steganalysis tool, which gives the analyst a better understanding of the detection results, especially when he has no prior information about the false positive rate of the tool

PRIS: Practical robust invertible network for image steganography

Image steganography is a technique of hiding secret information inside another image, so that the secret is not visible to human eyes and can be recovered when needed. Most of the existing image steganography methods have low hiding robustness when the container images affected by distortion. Such as Gaussian noise and lossy compression. This paper proposed PRIS to improve the robustness of image steganography, it based on invertible neural networks, and put two enhance modules before and after the extraction process with a 3-step training strategy. Moreover, rounding error is considered which is always ignored by existing methods, but actually it is unavoidable in practical. A gradient approximation function (GAF) is also proposed to overcome the undifferentiable issue of rounding distortion. Experimental results show that our PRIS outperforms the state-of-the-art robust image steganography method in both robustness and practicability. Codes are available at https://github.com/yanghangAI/PRIS, demonstration of our model in practical at http://yanghang.site/hide/

Survey of the Use of Steganography over the Internet

This paper addressesthe use of Steganography over the Internet by terrorists. There were ru-mors in the newspapers that Steganography is being used to covert communication between terrorists, without presenting any scientific proof. Niels Provos and Peter Honeyman conducted an extensive Internet search where they analyzed over 2 million images and didn’t find a single hidden image. After this study the scientific community was divided: some believed that Niels Provos and Peter Honeyman was conclusive enough other did not. This paper describes what Steganography is and what can be used for, various Steganography techniques and also presents the studies made regarding the use of Steganography on the Internet.Steganography, Secret Communication, Information Hiding, Cryptography

The XBOX 360 and Steganography: How Criminals and Terrorists Could Be Going Dark

Video game consoles have evolved from single-player embedded systems with rudimentary processing and graphics capabilities to multipurpose devices that provide users with parallel functionality to contemporary desktop and laptop computers. Besides offering video games with rich graphics and multiuser network play, today\u27s gaming consoles give users the ability to communicate via email, video and text chat; transfer pictures, videos, and file;, and surf the World-Wide-Web. These communication capabilities have, unfortunately, been exploited by people to plan and commit a variety of criminal activities. In an attempt to cover the digital tracks of these unlawful undertakings, anti-forensic techniques, such as steganography, may be utilized to hide or alter evidence. This paper will explore how criminals and terrorists might be using the Xbox 360 to convey messages and files using steganographic techniques. Specific attention will be paid to the going dark problem and the disjoint between forensic capabilities for analyzing traditional computers and forensic capabilities for analyzing video game consoles. Forensic approaches for examining Microsoft\u27s Xbox 360 will be detailed and the resulting evidentiary capabilities will be discussed. Keywords: Digital Forensics, Xbox Gaming Console, Steganography, Terrorism, Cyber Crim

Modern Techniques for Discovering Digital Steganography

Digital steganography can be difficult to detect and as such is an ideal way of engaging in covert communications across the Internet. This research paper is a work-in-progress report on instances of steganography that were identified on websites on the Internet including some from the DarkWeb using the application of new methods of deep learning algorithms. This approach to the identification of Least Significant Bit (LSB) Steganography using Convolutional Neural Networks (CNN) has demonstrated some efficiency for image classification. The CNN algorithm was trained using datasets of images with known steganography and then applied to datasets with images to identify concealed data. The algorithm was trained using 5000 clean images and 5000 Steganography images. With the correct configurations made to the deep learning algorithms, positive results were obtained demonstrating a greater speed, accuracy and fewer false positives than the current steganalysis tools