نشریه منادی امنیت فضای تولید و تبادل اطلاعات (افتا)
سال پنجم شماره 2 (پیاپی 10، پاییز و زمستان 1395)

In recent years the security of SHA-3[1] is one of the most interesting topics in the field of cryptography. Cryptography uses Hash functions in different ways. Thus the security of Hash functions against different attacks is of vital importance. Several attacks and many analysis have been applied to SHA-3 till now but none of them could break it theoretically or practically. Keccak relies on a Sponge architecture.
In this paper, we focus on differential fault analysis attack and we review the latest attacks on SHA-3. Specifically, we describe cube attack, differential fault analysis and also describe zero-sum distinguisher attack and pre-image attack by using linear structures.

The Identity Management System (IDM) is a set of policies, rules, procedures, and systems that manage authentication, access control, and audit activity based on digital identity. In the Identity Management System, given the storage of user identity attributes in the identity provider, users will lose their physical and traditional control over their personal identity, and on the other hand, user attributes are subject to more attacks from The inside of the system and the external attackers. Therefore, to ensure user's privacy control is keeping awareness of the release of his / her identity information, So providing security mechanisms in the area of privacy is essential. The current mechanisms have failed to satisfy users confidence in maintaining the security and privacy associated with their identity information. The designs presented in this area will increase user intervention and involvement during system interactions , and the user must act as an interface role. The Problems of the proposed designs, the high computational burden on a part of the system. In this article, the process of improving privacy control and user awareness for solving problems has been investigated.

In this paper, one of the most important challenges in energy smart grids – Denial of service for critical time messages – is addressed. In order to explain and solve this issue, we have described different communication structures for conveyed messages in energy smart grids, various proposed communication technologies, different types of jammings, and variety of conveyed messages in grid. Also, depending on communication technology and jamming in use, different situations of jamming is explored. To describe jamming problem, Gambler’s ruin problem solving theory is used. To eliminate this vulnerability, the least rate of invalid messages is calculated for the worst situation. TACT technic in he least camouflage traffic load in grids is used to match this problem to real world.

Data collection and storage has facilitated by the growth in electronic services, and has led to recording vast amounts of personal information in public and private organization's databases. These records often include sensitive personal information (such as income and diseases) and must be covered from others access. But in some cases, mining the data and extraction of knowledge from these valuable sources, creates the need for sharing them with other organizations. This would bring security challenges in user's privacy. “Privacy preserving data publishing” is a solution to ensure secrecy of sensitive information in a data set, after publishing it in a hostile environment. This process aimed to hide sensitive information and keep published data suitable for knowledge discovery techniques. Grouping data set records is a broad approach to data anonymization. This technique prevents access to sensitive attributes of a specific record by eliminating the distinction between a number of data set records. In this paper an overview of privacy preserving Data Publishing Techniques will be presented.

In this paper, the image steganography based on LSB and pixel classification is reviewed. Then, the method for steganography information in image is presented. This method based on LSB. Our purpose of this paper is to minimize the changes in cover image. At the first, the pixels of the image are selected to hiding the message; second complemented message will be hidden in LSB of selected pixels. In this paper, to solve some problems LSB method and minimize the changes, pixels categorized based on values of bits of second, third, fourth. In each category, ratio of changed pixels to unchanged pixels is calculated. If the ratio is greater than one, the LSB of that category are reversed and those changes reach at least. Mean Square Error and Peak Signal to Noise Ratio are two criterions to evaluate stego-image quality. PSNR and MSE of proposed method in comparison with simple LSB method, are respectively growth rate 0.13 percent and reduction rate 0.19 percent.

Location-based services (LBSs) provide appropriate information based on users’ locations. These services can be invoked by an individual user or a group of users. Using these services requires users to reveal their locations; thus, providing uses’ location privacy during the use of these services is an important issue. There are many works to protect users’ location privacy. In this paper, we have reviewed the related works to provide the location privacy for a group of users during the use of LBSs. We have classified them into two categories: the first category consists of the solutions that protect an individual user location privacy through group formation, while the second category contains the specific solutions to provide group location privacy. We have then analyzed and compared the performance and security properties of the related works, and have identified the open issues and future works in this field.