Advanced Defense Science and Technology
Year:2011 | Volume:2 | Issue:2 (4)|Papers Count:9

In recent years, Cyber Warfare has been one of the most essential war scenes for intelligence and military organizations. As the volume of data is increased, data stream processing and data security would be the basic requirements of military enterprises. Although, by data encryption no one can have access to data contents, but adversaries can delete some records from data stream or add some counterfeit records in it without any knowledge about records contents. Such attacks are called integrity attacks. Because integrity control in DSMS is a continuous process, it may be categorized in passive defense activities. In this paper, we present a probabilistic auditing model for integrity control of received stream results via an unsecured environment. In our architecture, users and data stream owners are trusted and channels are unsecured. The server is considered a black box and auditing process is fulfilled by contribution between data stream owner and users. We exploit existing Data Stream Management Systems (DSMS) without any modification. Our method has no significant cost on users side and detects integrity attacks accurately and rapidly. Correctness and convergence of our probabilistic algorithm is proved and our evaluation shows very good results.

Today, all businesses, public or private, profit or non-profit are exposed to different types of unpredictable and unpreventable events and crisis. Passive defense projects measures focus on a specific approach of challenging with accidents occurred in wars and try to reduce vulnerabilities of task force and critical, sensitive and important assets. In this paper, organizational agility as one of the best methods is identified and analyzed. Organizational agility can be accounted among the key factors of passive defense techniques. The method of research is applied looking its goal and is explorative-analytic in terms of methodology. In this study, agility capabilities are reviewed and are classified using factor analysis. Then, using neural network techniques, effect of every indicator on the level of agility is also analyzed. After that, by using charts and analysis of matrix of impact coefficients, interaction of these factors is investigated. The results show that the factors of management and organizational structure have the most important influence on the level of organizational agility. These results also indicate that the competence and accountability indicators can continuously increase the level of agility. According to the analysis chart, production and product design performance indicators alone cannot make a considerable change in the amount of agility. But by reducing these indices, level of agility is reduced too. Flexibility and speed indices can affect the alteration of the agility level in an organization.

Independent object test is one of the important steps in the object-oriented software test. This kind of test is faced with two problems: firstly, the object which is under test may call methods of other objects and therefore, the independent test of the object becomes impossible. Secondly, the called methods may be time-consuming and as a result the test of the object takes a long time. In order to overcome these problems, a useful method is to use the faked object which simulates the called methods. Faked objects are usually implemented using a table. This table-based implementation results in different problems such as time-consuming table search operation, and more importantly, inability to exact simulation of called methods. Besides, test samples are rare and therefore automatic generation of test samples which span all the code paths within a method has become a challenging problem. In this paper, a new artificial neural network-based faked object is proposed which solves the two above-mentioned problems. This paper contains two proposed sections: in the first section, the operation of linear functions which are used in programs is simulated. In the second section, the best set of input parameters which are needed to train the artificial neural network of faked object is determined optimally using genetic algorithm. The superiority of the proposed methods is confirmed using different experiments for mathematical, logical and discrete functions.

Information security is one of the important aspects of passive defense and cryptography has an undeniable role in realization of this security. Therefore, the main aim of using cryptographic hash functions is the integrity of information. Linearization is one of the important techniques in cryptanalysis of the hash functions that used for cryptanalysis of many hash functions. In this paper, we use idea of the cryptanalysis method with linear algebra and find some differential patterns for a linear variant of MD4 (LMD4) with a new search algorithm. Then using one of the patterns we find a collision for LMD4. Also we define another simplified variant of MD4 (CMD4) and present a successful collision attack with a complexity of 235on the CMD4 by using one of the so-called patterns is achieved. Finally, the collision attack on the MD4 is reconsidered.

Performance and capabilities of security forces during operations depend strictly on their ability in gaining information from the desired resources. Therefore, these forces always try to improve their productivity and efficiency using telecommunications and electronic surveillance systems. In surveillance systems, coding detection is done after identification of modulation. Accurate and timely recognition of coding in these systems is so critical that the performance of these systems is tied to it. This paper presents an algorithm that is based on entropy and information theory and is able to detect block and convolution codes. Simulation results show that the proposed algorithm is able to detect coding type in the Additive White Gaussian Noise channels (AWGN) with a minimum signal to noise ratio of 3dB, in binary symmetric channel (BSC) with an error probability of less than 0.1 and in binary erasure channel (BEC) with an error probability of less than 0.2.

Information security is one of the most important defensive issues that prevents the intruders' attacks to the privacy of organizations valuable data. Cryptology is one of the most powerful tools of Passive defence that assures the security of communication and information technology. In this paper, we propose a new image encryption scheme using chaotic maps to protect the distribution of digital images in an efficient and secure way. The new encryption scheme is implemented using MATLAB to check its efficiency. Moreover, a series of tests and some comparisons have been performed to justify efficiency of image encryption method. These tests included key space analysis, psychophysical experiments, histogram analysis, information entropy, encryption quality, correlation analysis, differential analysis and key sensitivity analysis. Simulation experiment has validated the effectiveness of the proposed system.

In order to provide the possibility of defense against maneuvering targets and providing better opportunity for decisions, a general structure for different maneuvers of targets have been provided in this paper. Moreover, variety of trajectories is simulated from radar perspective and the maneuver determination is considered carefully. In order to detect and track the targets trajectory to perform a proper defense, the targets motion must be simulated so that the tracking is to be done with minimal error. In order to present a general structure for maneuvers of targets, in this paper, different models for targets trajectory in one, two and three-dimensional forms for maneuvering and non-maneuvering targets are studied and simulated. As an innovation, effects of detection and false alarm probabilities were applied to the simulations. For all the presented models, trajectory simulation was done and the results are summarized in diagrams in this paper. The results can be used for evaluating different tracking algorithms in different SNRs.

Despite the great advances in Service Oriented Architecture in recent years, it is still facing a number of challenges. One of the main challenges of this architecture is the extraction and identification of services and compliance of identified services with business goals of the organization. In this paper, a method is presented to solve the problems noncompliance of services with the objectives of the organizations. In this method, after identification of the services, the tree of goals is produced and the target–service matrix is created. By examining this matrix, two important issues are determined. First, lack of coverage of organization targets by the identified services and second, non compatibility of identified services with organizational goals. The method proposed in this paper can be used for ensuring compliance of services with organizational goals.

Group key exchange protocols play main role in group applications such as computer networks, telecommunication and military systems. Given the wide range of usage of group applications, research and design of these protocols can play an important role in securing international exchanges, trade and military issues. Most existing group key exchange protocols establish multi-party or group key exchange protocols based on extending the two party well known Diffie-Hellman key exchanges. The security of these protocols is based on this assumption that difficulty of solving group Diffie-Hellman problem can be reduced to the difficulty of two party Diffie-Hellman problems. In spite of this assumption, Group key exchanges are not simply extension of two party protocols. In fact there are many differences and challenges that must be considered in design and implementation of these protocols. This difference is due to essential difference between peer to peer communication and group communication. In group communication in addition to considering the main goal e.g. obtaining group session key, consideration of group member changing is important too. In this paper, a Dynamic ID-based Group Key Agreement protocol based on Weil pairing is proposed. This complete ternary tree structure is used and dynamic changes in group are considered too. Finally we show that the proposed protocol is more efficient than other protocols with similar structure and also satisfies all known security requirements.