Steganography is largely used in information security systems. In steganography, the goal is to hide the information such that only the sender and receiver are aware of the communication and information. Steganography is carried out on different media such as image, sound and text. It can be performed in both transform and spatial domains. In transform domain methods, first the cover image is transformed into a different domain using, for example, a frequency transform. Then, the secret message is embedded in the conversion coefficients. In this paper, a new steganography method based on the transform domain is proposed to conceal text in an HSV color image. After converting the image to HSV, it is divided into blocks and the mixed column transfer is applied on each block. The secret message is embedded in the transferred columns. Simulation results and comparisons show the high capacity and increased security of the proposed method.

In recent years, watermarking is usually used to send military information in the form of images, videos, and natural sounds. The importance of military information’s hiding causes to propose new algorithms for these applications. However, extraction techniques are available in parallel with aforementioned watermarking algorithms. Due to the high importance of submarines’ top-secret information for naval forces, in this paper, combined technique that consists of Advanced Encryption Standard (AES) and Discrete Cosine Transform (DCT) is used to enhance the security of side scan sonar imagery information. Using this combined algorithm, the ability of information detection and decoding will be extremely difficult

This study is aimed to investigate effects of ambiguity and complexity of financial statements on the type of auditor strategies for dealing with audit risk increase. Complexity of financial statements leads to an ambiguous and misunderstanding information for investors; also, it can be used as an approach for hiding information. Therefore, auditors should use appropriate mechanisms to assess desirability of financial information and protect themselves against audit risk increase. The sample consists of 832 observations (year-firm) during the period 2011 to 2018. The study examines effects of readability of financial statements on audits’ fee, report lag, opinion and rotation. The findings show that more complexity and ambiguity of financial statements results in longer audit processes, more fees and more audit report lag. Findings also show that auditors use qualified opinions in a reaction to ambiguity in financial statements in order to reduce the risk of legal litigation. However, according to findings, financial statements complexity does not result in using client non-acceptance strategy by auditors.

Steganography is a branch of covert communication science, that the purpose is to hide the existence of information.Versus,the purpose of steganalysis is to detect and/or estimate potentially hidden information from observed data with little or no knowledge about the steganographic algorithm or its parameters. Although, the color images is common and have high capacity steganography, but researches in hiding information in color images is less than grayscale images. In this article, we have studied steganography and steganalysis methods in color images using color space information (such as RGB, YUV, YIQ, YCbCr and HSV color space) and proposed new methods in two domains. In steganography domain, we have proposed a simple and robust method for hiding information in the YUV and YCbCr color images using color spaces, that recognition of the message has become more difficult due to the use of conversion coefficients. The proposed method is evaluated by several famous steganalysis, and the results show that resistance of this method enhanced in comparison RGB color space. In steganalysis domain,we have examining the different color spaces and we have proposed a new general steganalysis method that based on spatial correlation of adjacent pixels in different color spaces components. It is independent of the type of steganography designed and has good detection. In general, the results of the two methods is highlights the effective and appropriate use of hiding information in color images in color space.

In the image stegenography, the distortion of stego image will be increased by increasing the number of embedded bits and this makes the enemy be much more suspicious about the existence of secret information in the images. One can use the matrix embedding technique to alleviatethis problem which can be done by dividing the cover image into some blocks and limiting the changes in each block.However, the embedding capacity will be limited by this technique. In this article, a solution to this problem (limited embedding capacity), a modified version of Fan’s method, is presented.In this technique, the maximum number of changes in each block is chosen to be 2 instead of 1 in Fan’s technique which leads to reducing the blocks length and increasing the embedding capacity.The results revealed that for a given capacity, the stego image distortion is decreased and the embedding capacity is increased in compared with the other existing methods in this field. Also, thestego images have high PSNR along with high vision quality which leads to more security.

Market transparency can be defined as a "timely and reliable trend of economic, social and political information available to those who interest in market". Although most economists have explained the feature of transparency or confidential information for healthy competition market have been defined, most economists admit that most markets suffer from lack of information. They have proposed such strategies like supplier's signaling, organizing institutions and state's management and supervision as a means to compensate this lack of information in market. It seems that capitalist economy cannot compensate this lack by relying on its principles.In Islamic market, the term "honesty" is a moral virtue and a graded perfection with a foundation and value load which are not found in transparency. It is not only the characteristics of market but also of the agents of the market that should be considered. By honesty, we mean its broad meaning, that is, honesty in terms of intention, conduct, and structure. In a market in which honesty is dominant, both sides of transaction have a sense of quiescence towards each other's behavior and no one of them keeps things secret while purchasing goods. If there is a mistake, it can be compensated through a certain market mechanism.

The growth of Internet and computer networks has led to the ease of information transfer. This development has also caused some problems due to the fact that in network environments, data may be snooped while transferring from the sender to the receiver. So, it is always necessary to provide information security and in order to achieve this goal, steganography plays an important role. Network steganography is a method that uses network protocols. Many techniques for network steganography have been suggested up to this time so that familiarity with different algorithms, as well as recognizing the advantages and disadvantages of each of them, are required for researchers in this field who wish to introduce a new approach to steganography or to propose a new method of steganalysis. In this paper, it has been attempted to describe the various ideas behind network steganography methods in terms of two different classifications, and the result of the research have been presented. Although it would be ideal to devise a method which satisfies the three steganography evaluation criteria: capacity, undetectability and robustness simultaneously, but bearing in mind the conflict between them, a method can be proposed for each application which excels in the criterion that is most relevant in that application.

Analysts used file signature comparison to detect malware and analyze the behavior of the executable file in the past. To prevent signature examination, the authors of the new and advanced malware used obfuscation methods to hide information, of which packaging is the most important and the most efficient one. This method encrypts and compresses the code, without harming the behavior of the original executable file and the code is obscure until it is executed. The methods that are now used to unpack these files are often methods that are specially designed for each type of packer for that file. There are other methods, such as Renovo and OmniUnpack for reopening that are known as public reopens, and actually cover the weakness of previous approaches which is the need to know the type of packager, but their main problem is finding the original point. The main entry of the program is the end of the unpacking section. Our approach to fix this problem is a method that detects this point using tracking memory pages and monitoring pages, then executes it, and then dumps the memory for creating a new file that has been unpacked. Our method has two advantages: first, there is no need for knowledge of packaging type, and second it can also be used for packers that are created in the future. Finally, in the evaluation section, we have shown that this method has a very high performance for current packers and more than 90% of them can be unpacked with it, so it can be used on an antivirus engine.

This paper investigates digital data hiding schemes. The concept of information hiding will be explained at first، and its traits، requirements، and applications will be described subsequently. In order to design a digital data hiding system، one should first become familiar with the concepts and criteria of information hiding. Having knowledge about the host signal، which may be audio، image، or video and the final receiver، which is Human Auditory System (HAS) or Human Visual System (HVS)، is also beneficial. For the speech/audio case، HAS will be briefly reviewed to find out how to make the most of its weaknesses for embedding as much data as possible. The same discussion also holds for the image watermarking. Although several audio and image data hiding schemes have been proposed so far، they can be divided into a few categories. Hence، conventionalschemes along with their recently published extensions are introduced. Besides، a general comparison is made among these methods leading researchers/designers to choose the appropriate schemes based on their applications. Regarding the old scenario of the prisoner-warden and the evil intention of the warden to eavesdrop and/or destroy the data that Alice sends to Bob، there are both intentional and unintentional attacks to digital information hiding systems، which have the same effect based on our definition. These attacks can also be considered for testing the performance or benchmarking، of the watermarking algorithm. They are also known as steganalysis methods which will be discussed at the end of the paper.