Network Perimeter Research Articles

Real-time network visibility and operationalising threat intelligence for cybersecurity breach detection

Since the World Wide Web was first commercialised around 1993–1994 information, data and communications have moved from physical to digital for all. It then rapidly became apparent that sensitive information could be accessed on networks within organisations via their internet connections. IT security then became a concern for all organisations great and small and putting in place network perimeter security and reporting was then enough to keep these breaches at bay. Today networks are very different again, there is no known perimeter for most with the usage of mobile devices, cloud apps and virtual machines as well as more traditional network infrastructure. IT security departments struggle to secure their networks as 80% of the time it is not known, where they are vulnerable, exactly what devices are present and when and in most cases there is little information on how breaches occur. The author examines why these networks are unknown, how criminals gain access to sensitive information and data, how to combat and know breaches, gather threat intelligence and have the right real-time analysis on exactly what activity is passes across organisations networks.

Network Security using Linux Intrusion Detection System

Attacks on the nation’s computer infrastructures are becoming an increasingly serious problem. Firewalls provide a certain amount of security, but can be fooled at times by attacks like IP spoofing and the so called authorized users. So an intelligent system that can detect attacks and intrusions is required. The tool GRANT (Global Real-time Analysis of Network Traffic) being a Linux based Intrusion Detection System(LIDs), takes the advantage of the security of a Linux box and secures the other nodes in the perimeter of the network. It is capable of detecting intrusions and probes as and when they occur and capable of responding to “already” successful attacks, thus causing minimal or no damage to the entire network. For better performance, this Linux Intrusion Detection System should be part of a defense in depth strategy such as Firewall and Intrusion Prevention..

The Geometric Efficient Matching Algorithm for Firewalls

Since firewalls need to filter all the traffic crossing the network perimeter, they should be able to sustain a very high throughput, or risk becoming a bottleneck. Firewall packet matching can be viewed as a point location problem: Each packet (point) has five fields (dimensions), which need to be checked against every firewall rule in order to find the first matching rule. Thus, algorithms from computational geometry can be applied. In this paper, we consider a classical algorithm that we adapted to the firewall domain. We call the resulting algorithm “Geometric Efficient Matching” (GEM). The GEM algorithm enjoys a logarithmic matching time performance. However, the algorithm's theoretical worst-case space complexity is O(n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> ) for a rule-base with n rules. Because of this perceived high space complexity, GEM-like algorithms were rejected as impractical by earlier works. Contrary to this conclusion, this paper shows that GEM is actually an excellent choice. Based on statistics from real firewall rule-bases, we created a Perimeter rules model that generates random, but nonuniform, rule-bases. We evaluated GEM via extensive simulation using the Perimeter rules model. Our simulations show that on such rule-bases, GEM uses near-linear space, and only needs approximately 13 MB of space for rule-bases of 5,000 rules. Moreover, with use of additional space improving heuristics, we have been able to reduce the space requirement to 2-3 MB for 5,000 rules. But most importantly, we integrated GEM into the code of the Linux iptables open-source firewall, and tested it on real traffic loads. Our GEM-iptables implementation managed to filter over 30,000 packets-per-second on a standard PC, even with 10,000 rules. Therefore, we believe that GEM is an efficient and practical algorithm for firewall packet matching.

Perimeter discovery in wireless sensor networks

In this paper, we focus on the perimeter detection problem using wireless sensor networks, as perimeter detection has a wide range of uses in several areas. We present a decentralized localized algorithm where sensor nodes determine if they are located along the perimeter of a wireless sensor network. Our proposed algorithm uses the location neighborhood information in conjunction with the Barycentric technique to determine if the sensor node enclosed by neighboring nodes, and consequently, if it is located within the interior of the wireless sensor network. We define performance metrics to analyze the performance of our approach and the simulation shows that the algorithm gives fairly accurate results.

Out-of-Network Events Can Be of Great Importance for Improving Results of Local Earthquake Tomography

In most local earthquake tomography (LET) studies the data are selected according to the azimuthal-gap (GAP) criterion, which means rejecting all the sources outside the station network perimeter. In this article I show that in some cases this cri- terion is inappropriate and can be a reason for significant decimation of the relevant data, in turn leading to lower quality inversion results. This study presents several qua- litativeandquantitativeargumentsforwhytheGAPcriterionisnotadequate.Thefactof great importance to out-of-network events for improving the results of tomographic inversion is supported by synthetic testing using realistic distribution of events in the area of Central Java and station locations according to the Merapi Amphibious Ex- periments project. I consider three models with different criteria of event selection: (1) dataset with GAP < 180°, (2) dataset with GAP < 280°, and (3) dataset with all events within a radius of 5°. The synthetic modeling reproduces the real situation when neither coordinates of sources nor starting 1D models are initially known. The recon- structionresultsshowthatthebestresolutionisobtainedformodel3withalldataavail- able, while the worst solution is observed in model 1. This study demonstrates that the commonlyusedGAPcriterionthatrejectstheout-of-networkeventsisinjuriousforLET tomography. In future experiments and when reconsidering the old datasets, I encour- age the use of data from all events to improve the results of tomographic inversion, though at large distances from networks (at least, up to 400-500 km).

De-perimeterisation: inevitable and essential

In a world where employees are mobile, businesses are highly interconnected, and the internet is king, the difference between 'secure' private networks and 'insecure' public networks is blurring. To tackle the security challenges of this new way of doing business, security professionals need to de-perimeterise, focusing on data rather than the network, and phasing out traditional perimeter security. My business's employees are mobile, our applications are highly interconnected and we use ecommerce platforms, extranets and the web to communicate with suppliers, partners, and customers. So where is the perimeter of my network? And how do I protect it if I cannot define it?

A window to the world?

Web 2.0, cloud computing, AJAX, and web applications represent the future of internet use. As a result, web content has undergone an explosion as businesses integrate data and services and present complex internal IT systems to users on the outside of the network perimeter. This represents a risk to the network, as a poorly configured CMS means that network security can be quickly bypassed, data assets corrupted, user information accessed, and the network compromised. Organisations must share information that is public and protect information that is private. This seems to be a simple enough concept for the network manager. However, with Gartner research showing worldwide security software sales topping $10 billion in 2007 and Forrester predicting 21% of IT security budgets growing in 2009, security continues to be an afterthought – a bolt-on to network infrastructures rather than central to information strategy.

Open Wireless Networks on University Campuses

Open wireless networks raise privacy issues and entail increased risk of malicious attacks and illegal downloading activities. Such networks are nonetheless attractive-particularly to universities-because they enhance usability and thus expand access to nonsensitive system resources. At universities, such access brings numerous benefits to students, faculty, and the surrounding community alike. Here, the authors describe the challenges of removing individual user authentication requirements at the perimeter of a university network in which mobile device users access system resources over wireless links to the wired infrastructure. The authors discuss how to mitigate the security and privacy risks entailed in an open network of this sort, and also describe how IT departments can vary the network's degree of openness.

Collagen network changes in basilar artery in aging

The aim of this study was to examine and evaluate morphometrically age-related changes in collagen network in the tunica media of human basilar artery. Histological analysis of the basilar arteries obtained from 89 individuals, aged 20 to 85 years, was performed. The study has been carried out by standard histological technique; histological samples were stained with picrosirius red. Detailed quantitative analysis of collagen bundle network in the tunica media of basilar artery was performed. We analyzed collagen network area, perimeter and number of collagen bundles in the tunica media of the basilar artery. After investigation of age-related changes in collagen network area in men and women, we determined that in both genders collagen network area in the tunica media of the basilar artery increased with age. Analyzing the perimeter and number of collagen bundles in both genders by different age groups, it was found that they decreased with age. We found a statistically significant correlation between all the measured parameters and the age. The area of collagen bundles increased, the number and perimeter of collagen bundles decreased with age in both genders in the tunica media of human basilar artery. While aging, the structure of collagen bundle network became less branchy, collagen fibers merged, their cross section area enlarged.

Securing Wi-Fi networks with position verification: extended version

In this paper we investigate position-based enhancements to Wi-Fi network security. Specifically, we investigate whether Received Signal Strength (RSS) measurements can identify attempts at network access by malicious nodes exterior to an authorised network perimeter. We assume the malicious nodes will spoof their received or transmitted power-levels in attempts to circumvent standard position-based security techniques. We outline why residual analysis of the RSS measurements cannot robustly identify illegal network access requests. However, we show that by referring the residual RSS analysis to a 'claimed position', interior to the authorised perimeter, a robust position-based verification system for secure network access can be developed. Indoor systems based on RSS fingerprints and differential RSS fingerprints are studied. Outdoor systems under the assumption of log-normal shadowing are also investigated.

Sensible Network Protection

In recent years, concerns about computer security in general and network security in particular have become more and more relevant. Network administrators have grown increasingly insecure with the news - and sometimes their personal experiences - of virus propagations that shut down networks, black hats that posted confidential information on Web servers, and many other publicly known attacks. The solution Network Perimeter Security proposes to protect our assets focuses on defining and implementing security policy development instead of relying on often-improvised technological patches. So, the book's primary audience is the administrator who must deal with technology, devices, and users on one side and managers, budgets, and network responsibilities on the other. This book addresses a major problem of trying to protect a medium- or large-sized network: how can a computer-literate network administrator talk about security with a business-oriented manager.

On a framework for energy-efficient security protocols in wireless networks

Network security is an important issue especially in wireless networks where the network is open and the network perimeter is not exactly known. This makes wireless networks more vulnerable to attacks such as eavesdropping, message interception and modifications. Several security protocols designed for wired-line networks have been adopted for use in wireless networks. However, they may not be suitable for wireless networks and devices since scenarios and capabilities applicable to wired-line networks may not be valid in wireless networks. For example, wireless devices often have limited battery power, and performing several message exchanges used in typical wired-line security protocols may rapidly deplete the devices’ battery. Cryptographic primitives consume energy and could degrade the battery performance of wireless networks. In this paper, we classify energy saving mechanisms for security protocols in wireless networks. We apply these energy saving mechanisms to existing security protocols and demonstrate the reduction in energy consumption that is possible with the suggested approaches.

The Insider, Naivety, and Hostility: Security Perfect Storm?

Every year corporations and government installations spend millions of dollars fortifying their network infrastructures. Firewalls, intrusion detection systems, and antivirus products stand guard at network boundaries, and individuals monitor countless logs and sensors for even the subtlest hints of network penetration. Vendors and IT managers have focused on keeping the wily hacker outside the network perimeter, but very few technological measures exist to guard against insiders - those entities that operate inside the fortified network boundary. The 2002 CSI/FBI survey estimates that 70 percent of successful attacks come from the inside. Several other estimates place those numbers even higher.

Gross anatomy of network security.

Information security involves many branches of effort, including information assurance, host level security, physical security, and network security. Computer network security methods and implementations are given a top-down description to permit a medically focused audience to anchor this information to their daily practice. The depth of detail of network functionality and security measures, like that of the study of human anatomy, can be highly involved. Presented at the level of major gross anatomical systems, this paper will focus on network backbone implementation and perimeter defenses, then diagnostic tools, and finally the user practices (the human element). Physical security measures, though significant, have been defined as beyond the scope of this presentation.

Strategy for Designing Geodetic Network with High Reliability and Geometrical Strength

The main design criteria in a geodetic network are precision, reliability and strength, and economy. The proper design of geodetic networks is an integral part of the geodesist's task. The main goal of this paper is to suggest a strategy for designing a geodetic network to meet high reliability and geometrical strength criteria. In this context, a real 2D deformation monitoring scheme has been selected to evaluate its design criteria. The results indicate that the perimeter of a geodetic network is relatively weaker than the middle. This means that the perimeter observations are usually weaker than those in the middle, the maximum distortions are usually located on the edge netpoints, and the maximum robustness parameters belong to the perimeter of the network. A strategy has been recommended to counter this problem. The results also showed that the robustness parameters in rotation, shear, and scale are affected by redundancy numbers. Actually, the largest robustness parameters are due to the weak observations in the network.

IGNALINOS ATOMINĖS ELEKTRINĖS GEODINAMINIO POLIGONO NIVELIACIJA

Summary The perimeter of the levelling network is 65.5 km. The levelling network includes 110 bench-marks. Since 1989 the geodynamic polygon used to be levelled every year. The precision compensating level Ni 002 has been used. Characteristics of the network accuracy have been determined by analysis of disagreement in the results between direct and back levelling traverses. The mean correction of 1 km double levelling traverse obtained was equal to 0,3 mm on sunny hot days while on cloudy and chilly days it was 0,2 mm. The results of the investigation obtained shoved that accuracy of levelling is effected by the meteorological and optic conditions, but not by accuracy of readings.