Intrusion Prevention Systems (IPSs) have long been proposed as a defense against attacks that propagate too fast for any manual response to be useful. While purely-network-based IPSs have the advantage of being easy to install and manage, research have shown that this class of systems are vulnerable to evasion [70, 65], and can be tricked into filtering normal traffic and create more harm than good [12, 13]. Based on these researches, we believe information about how the attacked hosts process the malicious input is essential to an effective and reliable IPS. In existing IPSs, honeypots are usually used to collect such information. The collected information will then be analyzed to generate countermeasures against the observed attack. Unfortunately, techniques that allow the honeypots in a network to be identified ([5, 71]) can render these IPSs useless. In particular, attacks can be designed to avoid targeting the identified honeypots. As a result, the IPSs will have no information about the attacks, and thus no countermeasure will ever be generated. The use of honeypots is also creating other practical issues which limit the usefulness/feasibility of many host-based IPSs. We propose to solve these problems by duplicating the detection and analysis capability on every protected system; i.e., turning every host into a honeypot. / text

To address the overload conditions caused by the increasing network traffic volume, recent literature in the network intrusion detection and prevention field has proposed the use of clusters of network intrusion detection and prevention systems (NIDPSs). We observe that simple traffic distribution schemes are usually used for NIDPS clusters. These schemes have two major drawbacks: (1) the loss of correlation information caused by the traffic distribution because correlated flows are not sent to the same NIDPS and (2) the unbalanced loads of the NIDPSs. The first drawback severely affects the ability to detect intrusions that require analysis of correlated flows. The second drawback greatly increases the chance of overloading an NIDPS even when loads of the others are low. In this thesis, we address these two drawbacks. In particular, we propose two novel traffic distribution systems: the Correlation-Based Load Balancer and the Correlation-Based Load Manager as two different solutions to the NIDPS traffic distribution problem. On the one hand, the Load Balancer and the Load Manager both consider the current loads of the NIDPSs while distributing traffic to provide fine-grained load balancing and dynamic load distribution, respectively. On the other hand, both systems take into account traffic correlation in their distributions, thereby significantly reducing the loss of correlation information during their distribution of traffic. We have implemented prototypes of both systems and evaluated them using extensive simulations and real traffic traces. Overall, the evaluation results show that both systems have low overhead in terms of the delays introduced to the packets. More importantly, compared to the naive hash-based distribution, the Load Balancer significantly improves the anomaly-based detection accuracy of DDoS attacks and port scans -- the two major attacks that require the analysis of correlated flows -- meanwhile, the Load Manager successfully maintains the anomaly-based detection accuracy of these two major attacks of the NIDPSs.

To address the overload conditions caused by the increasing network traffic volume, recent literature in the network intrusion detection and prevention field has proposed the use of clusters of network intrusion detection and prevention systems (NIDPSs). We observe that simple traffic distribution schemes are usually used for NIDPS clusters. These schemes have two major drawbacks: (1) the loss of correlation information caused by the traffic distribution because correlated flows are not sent to the same NIDPS and (2) the unbalanced loads of the NIDPSs. The first drawback severely affects the ability to detect intrusions that require analysis of correlated flows. The second drawback greatly increases the chance of overloading an NIDPS even when loads of the others are low. In this thesis, we address these two drawbacks. In particular, we propose two novel traffic distribution systems: the Correlation-Based Load Balancer and the Correlation-Based Load Manager as two different solutions to the NIDPS traffic distribution problem. On the one hand, the Load Balancer and the Load Manager both consider the current loads of the NIDPSs while distributing traffic to provide fine-grained load balancing and dynamic load distribution, respectively. On the other hand, both systems take into account traffic correlation in their distributions, thereby significantly reducing the loss of correlation information during their distribution of traffic. We have implemented prototypes of both systems and evaluated them using extensive simulations and real traffic traces. Overall, the evaluation results show that both systems have low overhead in terms of the delays introduced to the packets. More importantly, compared to the naive hash-based distribution, the Load Balancer significantly improves the anomaly-based detection accuracy of DDoS attacks and port scans -- the two major attacks that require the analysis of correlated flows -- meanwhile, the Load Manager successfully maintains the anomaly-based detection accuracy of these two major attacks of the NIDPSs.

<p>Ericsson’s Packet Radio Access Network (PRAN) is a network solution for packet transport in mobile networks, which utilizes the Internet Protocol (IP). The IP protocol offers benefits in responsiveness and performance adaptation to data bursts when compared to Asynchronous Transfer Mode (ATM), which is still often used. There are many manufacturers / operators providing IP services, which reduce costs. The IP’s use on the Internet brings greater end-user knowledge, wider user community and more programs designed for use in IP environments. Because of this, the spectrum of possible attacks against PRAN broadens. This thesis provides information on what protection an Intrusion Prevention System (IPS) can add to the current PRAN solution.</p><p>A risk analysis is performed to identify assets in and threats against PRAN, and to discover attacks that can be mitigated by the use of an IPS. Information regarding placement of an IPS in the PRAN network is given and tests of a candidate system are performed. IPS features in hardware currently used by Ericsson as well as missing features are pinpointed . Finally, requirements for an IPS intended for use in PRAN are concluded.</p>

Katalogtjänster är och förblir en central och kritisk del i informationssystem. I katalogtjänsterna samlas stora mängder information om användare och behörigheter för respektive användare. I högriskmiljöer, där bland annat hemlig och annan skyddsvärd information samlas, är katalogtjänsterna i en utsatt situation. Om en katalogtjänst svarar fel på en resursförfrågan kan konsekvenserna vara stora. Arbetet grundade sig i att med hjälp av olika säkerhetshöjande åtgärder bygga upp ett mer robust system för att skydda katalogtjänsten mot att behörighetsprinciperna bryts och ger obehörig personal eller andra aktörer tillgång till skyddsvärda resurser. Arbetet syftade till att öka medvetenheten kring de hypotetiska sårbarheterna som finns i en katalogtjänst och baserat på detta resultera i hur de potentiella sårbarheterna i åtkomstprinciperna kan motverkas eller mildras. För att uppnå detta resonerades det fram två testfall varav ett teoretiskt. Dessa byggde på att ett Intrusion Prevention System (IPS) implementerades i ett av testfallen och en brandvägg i det andra teoretiska fallet. Båda åtgärderna implementerades i trafikflödets riktning i respektive nätverkssegment för att kontrollera användarnas behörigheter i realtid. Testfallen byggdes upp simulerat med hjälp av bland annat GNS3 och Virtualbox. Det experiment som upprättades med IPS:en som huvudkomponent gav ett positivt utfall där enheten med hjälp av en uppsättning regler kunde utläsa specifika trafikflöden till resurser som den avsedda användaren inte hade tillgång till och baserat på detta utföra olika typer av åtgärder. Experimentet med brandväggen gav däremot inte önskat resultat, detta berodde på att det inte fanns stöd för den eftersökta funktionaliteten i de brandväggar med öppen källkod som undersöktes för implementationen. Det resultat som genererades med hjälp av IPS:ens förmåga att analysera trafik i realtid och baserat på detta utföra fördefinierade åtgärder betyder att det effektivt kan byggas upp ytterligare en barriär av skydd utöver katalogtjänstens egna säkerhet. Vidare medför detta även att om en IPS implementeras krävs det att två av varandra oberoende säkerhetsåtgärder fallerar innan ett felsvar realiseras vilket är att användaren får tillgång till resursen.

Ericsson’s Packet Radio Access Network (PRAN) is a network solution for packet transport in mobile networks, which utilizes the Internet Protocol (IP). The IP protocol offers benefits in responsiveness and performance adaptation to data bursts when compared to Asynchronous Transfer Mode (ATM), which is still often used. There are many manufacturers / operators providing IP services, which reduce costs. The IP’s use on the Internet brings greater end-user knowledge, wider user community and more programs designed for use in IP environments. Because of this, the spectrum of possible attacks against PRAN broadens. This thesis provides information on what protection an Intrusion Prevention System (IPS) can add to the current PRAN solution. A risk analysis is performed to identify assets in and threats against PRAN, and to discover attacks that can be mitigated by the use of an IPS. Information regarding placement of an IPS in the PRAN network is given and tests of a candidate system are performed. IPS features in hardware currently used by Ericsson as well as missing features are pinpointed . Finally, requirements for an IPS intended for use in PRAN are concluded.

Context. Cloud computing (CC) is developed as a Human-centered computing model to facilitate its users to access resources anywhere on the globe. The resources can be shared among any cloud user which mainly questions the security in cloud computing. There are Denial of Service and Distributed Denial of Service attacks which are generated by the attackers to challenge the security of CC. The Next-Generation Intrusion Prevention Systems (sometimes referred as Non-Traditional Intrusion Prevention Systems (NGIPS) are being used as a measure to protect users against these attacks. This research is concerned with the NGIPS techniques that are implemented in the cloud computing environment and their evaluation. Objectives. In this study, the main objective is to investigate the existing techniques of the NGIPS that can be deployed in the cloud environment and to provide an empirical comparison of source mode and destination mode in Snort IPS technique based on the metrics used for evaluation of the IPS systems. Methods. In this study, a systematic literature review is used to identify the existing NGIPS techniques. The library databases used to search the literature are Inspec, IEEE Xplore, ACM Digital Library, Wiley, Scopus and Google scholar. The articles are selected based on an inclusion and exclusion criteria. The experiment is selected as a research method for the empirical comparison of Source mode and destination mode of Snort NGIPS found through literature review. The testbed is designed and implemented with the Snort filter techniques deployed in the virtual machine. Results. Snort is one of the mostly used NGIPS against DoS and DDoS attacks in the cloud environment. Some common metrics used for evaluating the NGIPS techniques are CPU load, Memory usage, bandwidth availability, throughput, true positive rate, false positive rate, true negative rate, false negative rate, and accuracy. From the experiment, it was found that Destination mode performs better than source mode in Snort. When compared with the CPU load, Bandwidth, Latency, Memory Utilization and rate of packet loss metrics. Conclusions. It was concluded that many NGIPS of the cloud computing model are related to each other and use similar techniques to prevent the DoS and DDoS attacks. The author also concludes that using of source based and destination based intrusion detection modes in Snort has some difference in the performance measures.

The subject of the master's thesis is a design of security measures for securing of an industrial control system. It includes an analysis of characteristics of communication environment and specifics of industrial communication systems, a comparison of available technological means and a design of a solution according to investor's requirements.

abstract: Cloud computing is regarded as one of the most revolutionary technologies in the past decades. It provides scalable, flexible and secure resource provisioning services, which is also the reason why users prefer to migrate their locally processing workloads onto remote clouds. Besides commercial cloud system (i.e., Amazon EC2), ProtoGENI and PlanetLab have further improved the current Internet-based resource provisioning system by allowing end users to construct a virtual networking environment. By archiving the similar goal but with more flexible and efficient performance, I present the design and implementation of MobiCloud that is a geo-distributed mobile cloud computing platform, and G-PLaNE that focuses on how to construct the virtual networking environment upon the self-designed resource provisioning system consisting of multiple geo-distributed clusters. Furthermore, I conduct a comprehensive study to layout existing Mobile Cloud Computing (MCC) service models and corresponding representative related work. A new user-centric mobile cloud computing service model is proposed to advance the existing mobile cloud computing research. After building the MobiCloud, G-PLaNE and studying the MCC model, I have been using Software Defined Networking (SDN) approaches to enhance the system security in the cloud virtual networking environment. I present an OpenFlow based IPS solution called SDNIPS that includes a new IPS architecture based on Open vSwitch (OVS) in the cloud software-based networking environment. It is enabled with elasticity service provisioning and Network Reconfiguration (NR) features based on POX controller. Finally, SDNIPS demonstrates the feasibility and shows more efficiency than traditional approaches through a thorough evaluation. At last, I propose an OpenFlow-based defensive module composition framework called CloudArmour that is able to perform query, aggregation, analysis, and control function over distributed OpenFlow-enabled devices. I propose several modules and use the DDoS attack as an example to illustrate how to composite the comprehensive defensive solution based on CloudArmour framework. I introduce total 20 Python-based CloudArmour APIs. Finally, evaluation results prove the feasibility and efficiency of CloudArmour framework. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2014

Att skydda sin IT-miljö mot olika typer av intrång och attacker som till exempel trojaner,skadliga Java applets eller DoS attacker med hjälp av brandväggar och antivirusprogramär två viktiga lager i skalskyddet. I den här uppsatsen undersöks hur väl ett Intrusion Prevention System skulle kunna fungera som ett ytterligare lager i skalskyddet. Fokus ligger på hur väl IPS-systemet klarar av att avvärja attacker, hur mycket tid som går åt till konfigurering och drift för att få ett fungerande IPS samt hur prestandan i nätverket påverkas av implementationen. För att mäta hur väl IPS systemet klarar av att upptäcka och blockera attacker utförs två experiment där ett mindre nätverk attackeras på olika sätt. I det första experimentet skyddas infrastrukturen av en brandvägg och klienterna är utrustade med antivirusprogram. I det andra experimentet genomförs samma attacker igen fast med ett Snort IPS implementerat i nätverket. Resultatet av de genomförda experimenten visar att en IPS klarar att blockera ca 87% av attackerna, men nätverksprestandan påverkas negativt. Slutsatsen är att endast brandväggar och antivirusprogram inte ger ett fullgott skydd.