A new approach to covert communication via PDF files

[[abstract]]A new covert communication method via PDF files is proposed. A secret message, after being encoded by a special ASCII code and embedded at between-word and between-character locations in the text of a PDF file, becomes invisible in the window of a common PDF reader, creating a steganographic effect for secret transmission through the PDF file. Experimental results show the feasibility of the proposed method. (C) 2009 Elsevier B.V. All rights reserved

The Security of Arithmetic Compression Based Text Steganography Method

Security of a modern design of steganography on lossless compression isstudied in this paper. Investigation of a set of methods presented hereindicates that there are various approaches to establish a hidden and saferelationship with the minimum cost for text files. Although, steganography of information in text is one of the most difficult areas of steganography, many efforts were made in this regard. With regard to the spread of this category and existence of wide volume of approaches, this paper deals with comparison and evaluation of steganography security by a statisticalcompression method called arithmetic coding and other methods of textsteganography. Moreover, this method is available for audio-visual and video files. In addition, stego key was placed in a format that it would not arouse any suspicions. It is notable that this new method of steganography or rewriting and syntactic and semantic review does not reveal the secret message and results in 82.88% improvement in security.DOI:http://dx.doi.org/10.11591/ijece.v3i6.406

Forensic Analysis of Android Steganography Apps

The processing power of smartphones supports steganographic algorithms that were considered to be too computationally intensive for handheld devices. Several steganography apps are now available on mobile phones to support covert communications using digital photographs. This chapter focuses on two key questions: How effectively can a steganography app be reverse engineered? How can this knowledge help improve the detection of steganographic images and other related files? Two Android steganography apps, PixelKnot and Da Vinci Secret Image, are analyzed. Experiments demonstrate that they are constructed in very different ways and provide different levels of security for hiding messages. The results of detecting steganography files, including images generated by the apps, using three software packages are presented. The results point to an urgent need for further research on reverse engineering steganography apps and detecting images produced by these apps

Teknik penyembunyian mesej dalam steganografi teks menggunakan pendekatan warna RGB dan penempatan rawak

Steganography is a technique that protects the confidentiality and integrity of data in a protective medium from suspicion of hidden data. The hiding of a message in a text medium can be performed on various text attributes such as type, style, size, and font color to generate a stego text. This study have identified two main problems that lead to the suspicion towards the stego text which is the obvious change of colors of the generated stego and the static representation of the secret message characters using sequential selection of hiding location. Therefore, the main objective of this study is to propose the use of specific value for each combination of Red, Green, Blue (RGB) color to reduce the generated stego text obvious color changes. This study also recommends a dynamic secret message representation method based on a randomly selected character location. A Homophonic Cipher Table was adapted as a method to generate the dynamic secret message characters. Besides, the Second Quotient Remainder Theorem was proposed to convert the secret message characters into a 3D representation by mapping (x,y,z) values to RGB color. The RGB color cube model values of RGB(0,0,0) to RGB(15,15,15) were used to format a selected cover text characters using the Pseudorandom Number Generator. The performance of stego text produced in this study was evaluated using three main measures namely capacity, imperceptibility, and robustness. The results revealed that the proposed method produces a better performance of secret message hiding by 41.31% increase in capacity and the Jaro Winkler's scale imperceptibility score of 1. The performance of stego text is proven to be robust as there is no difference compared to the cover text before and after the compression process. In conclusion, the proposed method has successfully reduced the generated stego text obviousness in the change of colors that lead to suspicion of existence of hidden message. Beside, this method also capable of producing dynamic secret messages using a single cover text

A new approach to covert communication via PDF files

[[abstract]]A new covert communication method via PDF files is proposed. A secret message, after being encoded by a special ASCII code and embedded at between-word and between-character locations in the text of a PDF file, becomes invisible in the window of a common PDF reader, creating a steganographic effect for secret transmission through the PDF file. Experimental results show the feasibility of the proposed method. © 2009 Elsevier B.V. All rights reserved