With the increase in attacks, the different mechanisms in different layers of defense are applied in order to detect and prevent attacks. In this case we are encountered with massive amounts of alerts with low level and scattered information. Alert correlation is one of the solutions that are used to combine alerts and create a high level view of under controlled network security situations, and a lot of researches have been done in this field. In this paper, we describe the OSSIM and introduce its features. In addition with a combined approach to the alert correlation problem, a new categorization is done on the scientific researches and with respect to these researches, we described the process of alert correlation in the OSSIM and established a correspondence between components of the OSSIM and one of the researches. In most researches the focus is on the alerts correlation of intrusion detection systems, we have shown in this paper that the other resources are effective in multi-stage attacks correlation.

Trust and reputation are known social concepts which have an important role in human society. Nowadays, these concepts are also employed in computer science as computational trust and reputation systems (TRSs) that are able to compute the trustworthiness rank of entities based on a collection of experiments and recommendations. Since it is expected that a dishonest entity has a lower trust, the trust values can help the entities to detect and isolate the malicious or selfish entities. TRSs have been applied in many modern computer systems, and also are the most important tool in soft security as the next generation of security mechanisms. Despite the importance and applications of these systems, they are vulnerable to some kind of attack in which the attacker deceives the system using a sequence of misleading behavior. These attacks enable the attacker to manipulate the computation of trust values in his favor. A vulnerable system not only can’t help detecting the malicious entities, but also may be used by them to empower their attack. Hence, robustness evaluation is a critical step before using TRSs. Simulation and formal verification are two main approaches for robustness evaluation of TRSs. Despite the wide usage of simulation in evaluation of TRSs, it is an approximation method that can be used to validate the behavior of the system just for some particular computation paths. In contrast, formal verification based methods provide guarantees for the validation of the whole computation paths of the given system, thus not only their results are exact and provable but also may be used to find whole possible attacks against a given system. Considering the advantages of verification based methods, there is a narrow but progressing trend for proposing such methods in recent years. In this paper, both formal and simulation based methods for robustness evaluation of TRSs are reviewed and compared with each other.

In the past decade with distribution software such as browsers, online stores, Internet banking, electronic mail systems and the Internet, to carry out reverse engineering attacks, illegal use of illegal software or reproduce it is.A new attack techniques have failed and this creates competition between the attackers and software developers. So far, many techniques based architecture, hardware and software for this semester has been introduced to protect each aspect of the application process. In this paper, we introduce a variety of threats to software and then try to categorize and review of techniques to protect our software.

With emerging of the Internet, the way we communicate with each other has fundamentally revolutionized. The second development wave of the Internet is not about people, but will be about smart connected devices. Although more than a decade passes from the proposing of "Internet of Things" concept, the deployment of this concept has been done slowly for various reasons such as lack of required technologies development and security challenges. We must spend more time to understand the security challenges and available solutions, when we speak about smarter environments and technologies such as IoT. In this paper, we attempt to analysis existent threats and vulnerabilities in the area of security and privacy of Internet of Things using a systematic approach, while presenting a survey of the solutions proposed in the literature. Finally, research opportunities of this area will be discussed.

Recently, software defined networks have been introduced for innovation and flexibility in computer networks. They are widely used in infrastructure networks and data centers. Using these networks has advantages such as scalability, efficient bandwidth usage, reducing control traffic, better traffic engineering and etc., which are mainly due to their programmability. There are also some security challenges that often arise from the same property. Software defined networks reliability compared to traditional network reduces due to these challenges. Therefore, if software defined networks are not design based on a security architecture, they will be vulnerable against known cyber-attacks such as DDoS, spoofing, information disclosure and etc. In this paper, software defined network security challenges and corresponding solutions are reviewed. Moreover, some applications of software defined networks for security including network traffic separation, network flow access control, and secure routing are mentioned. In order to do security testing and evaluation of relevant security solutions we have explained how these networks are simulated.

The widespread use of information and communication technology in industrial control systems has exposed many cyber attacks to these systems. The first step in providing security solutions is to recognize the threats and vulnerabilities of a system at first. Therefore, in this work, after providing a general overview of the SCADA security, we provide a survey on actual cyber attacks from 2000 up to now. To be able to assess the risk of these attacks, we perform profiling them based on the target systems of the attack, the geographical area of it, the method used in the attack and its impact. This profiling provides a clear view of the most important security incidents in SCADA systems and could be useful in the defining suitable strategies for preventing and defending against the major SCADA security attacks.