Modeling Firewalls Using Hierarchical Colored Petri Nets

1997

This paper concentrates on one particular technological aspect of providing communications security, firewall technology. Currently firewall technology is a specialized engineering solution rather than a scientifically based solution.

2008

The task of configuring and updating a collection of firewalls has become so challenging that, for many networks, the cost of maintaining the firewall is prohibitive. This cost derives from the difficulty of avoiding subtle design errors in a complex and often verbose firewall policy. Analysis tools can reduce the burden on the administrator and improve security by identifying errors in the firewall configuration or even suggesting changes to the policy. Existing analysis tools suffer from many drawbacks which prevent ...

Lecture Notes in Computer Science, 2011

With the rapid progresses in trusted computing related research and application, many trusted computing based security mechanisms have been proposed to defend against threats in open, dynamic and distributed environments. These mechanisms are supposed to serve as the security foundations in the underlying systems. However, the correctness of these security mechanisms still require further examination and validation. We propose a Colored Petri Nets (CPN or CP-nets) based approach to model the trusted computing based secure system. In particular, with CPN, we model process management, data protection and late launch mechanisms in the systems. Further, as case studies we use these models to investigate the memory protection mechanism in TrustVisor and remote attestation based on dynamic root of trust, respectively; and the results demonstrate that our models are indeed capable of depicting real secure system based on trusted computing. With the advantages of CPN based modeling and analysis (e.g., graphical representation, well defined semantics and a large number of formal analysis methods), our models can well serve as the foundation for formal analysis on the security properties of trusted computing enhanced systems.

Colloquium Exactarum, 2020

Industrial Control Systems (ICS) networks offer a high level of automation combined with high levels of control, quality, and process improvement. Since network corporate users have to access the ICS environment, these networks have to be interconnected. However, this interconnection can introduce risks to the systems and manufacturing processes, which leads to the need to ensure the interconnection is done safely. The objective of this paper is to perform modeling and validation of a proposed secure interconnection between ICS and corporate networks using Colored Petri Networks (CPN). In addition to the best practices published in related works, this paper recommends some integrated features like the use of terminal server service, secure manual uplinks, and unidirectional security gateway to enhance environmental security. However, our main contribution is the validation process performed in a CPN, which made it possible to execute queries in the state space resulting from the simulation - that works as a proof of concept. As a result, the paper presents a secure and validated model of interconnection between ICS and corporate networks, capable of being applied to any interconnection environment. Keywords: ICS Network; Corporate Network; Secure Interconnection; Colored Petri Net.

2008

This dissertation describes a technique for formally analyzing a firewall security policy using a quasi-reduced multiway decision diagram model. The analysis allows a system administrator to detect and repair errors in the configuration of the firewall without a tedious manual inspection of the firewall rules. We present four major contributions. First, we describe a set of algorithms for representing a firewall rule set as a multi-way decision diagram and for solving logical queries against that model. We demonstrate the application of these techniques in a tool for analyzing iptables firewalls. Second, we present an extension of our work that enables analysis of systems of connected firewalls and firewalls that use network address translation and other packet mangling rules. Third, we demonstrate a technique for decomposing a network into classes of equivalent hosts. These classes can be used to detect errors in a firewall policy without apriori knowledge of potential vulnerabilit...

Role Based Access Control (RBAC) is one of the most used models in designing and implementation of security policies in large networking systems. The classical model doesn't consider temporal aspects which are so important in such policies. Temporal RBAC (TRBAC) is proposed to deal with these aspects. Although the elegance of these models, design a security policy remains a challenge. One is obliged to prove the consistency and the correctness of the policy. Using formal verification allows proving that the designed policy is consistent. In this paper 1 , we present a formal modelling/analysis approach for TRBAC policies. We use Timed Colored Petri Nets to model the TRBAC policy, and then CPN-tool is used to analyze the generated models. The analysis allows proving many important properties about the TRBAC security policy.

Journal of Advances in Computer Networks, 2015

With the rapid development of Internet, the security of networks becomes an important issue today and monitoring network traffic is necessary for realizing different purposes such as system performance, network debugging and/or information security. As a major measure to implement enterprise security, firewall technique ensures the security of local networks. Traditional firewall technologies have their own weaknesses in architecture, configuration, monitoring and management that affect to firewall performance. Furthermore, it lacks to deal with vague and uncertainty associated with filtering packets from outside. Architecture of a new kind of firewall, intelligence firewall is presented in this paper. The main contribution is to utilize Fuzzy Petri Net as a tool for modeling discrete event systems characterized by an imprecise knowledge. The graphical power of Petri Nets makes the packet filtering model easy to design, test, improve and maintain. Another contribution is to present 2-level fuzzy filtering algorithm to enhance ordering of filtering rules list that permits us to model the dynamic behavior of monitoring system concerning uncertainty associated with packet filtering. Experimental results for local network are given, which show the effectiveness of the suggested approach and demonstrate the enhancement of the firewall sensitivity against the risk coming from network traffics. Index Terms-Firewall, fuzzy petri net, packet filtering, access control list (ACL). I. INTRODUCTION With the advancement of computer technology and the wide spread use of computer networks, the security of internal network against attacks, illegitimate traffics and unauthorized access can be crucial to the success of the entire business operation. As firewalls are core element in network security, over the years, firewalls technology has become a major area of research in network security. A firewall is a combination of hardware and software used to implement a security policy governing the flow of traffic between two or more networks [1]. In its simplest form, a firewall acts as a security barrier to control traffic and manage connections between internal and external network hosts. Connections and service requests are either accepted or rejected based on a set of rules defined by the network administration security policy [2]. Firewall have many abilities like defines a single choke Manuscript

2013

In this paper, we propose Colored Petri Net (CoPNet) modeling approach by extending the attack trees with new modeling constructs and analysis approaches. CoPNet based attack model is flexible enough to model Internet intrusion, including the static and dynamic features of the intrusion. The process and rules of building CoPNet based attack model from AT are also presented. In order to evaluate the risk of intrusion, some cost elements are added to CoPNet based attack modeling. We show how attack trees can be converted and analyzed in CoPNets. Finally, we provide a malicious insider attacks as case study that illustrates the CoPNet approach.

International Journal of …, 2007

The integration of Software Fault Tree (SFT) which describes intrusions and Colored Petri Nets (CPNs) which specifies design, is examined for an Intrusion Detection System (IDS). The IDS under development is a collection of mobile agents that detect, classify, and correlate system and network activities. Software Fault Trees (SFTs), augmented with nodes that describe trust, temporal, and contextual relationships, are used to describe intrusions. CPNs for intrusion detection are built using CPN templates created from the augmented SFTs. Hierarchical CPNs are created to detect critical stages of intrusions. The agent-based implementation of the IDS is then constructed from the CPNs. Examples of intrusions and descriptions of the prototype implementation are used to demonstrate how the CPN approach has been used in development of the IDS.

Entropy, 2014

The aim of this article is to present an approach to develop and verify a method of formal modeling of cyber threats directed at computer systems. Moreover, the goal is to prove that the method enables one to create models resembling the behavior of malware that support the detection process of selected cyber attacks and facilitate the application of countermeasures. The most common cyber threats targeting end users and terminals are caused by malicious software, called malware. The malware detection process can be performed either by matching their digital signatures or analyzing their behavioral models. As the obfuscation techniques make the malware almost undetectable, the classic signature-based anti-virus tools must be supported with behavioral analysis. The proposed approach to modeling of malware behavior is based on colored Petri nets. This article is addressed to cyber defense researchers, security architects and developers solving up-to-date problems regarding the detection and prevention of advanced persistent threats.