Security, Edge and Cloud Lab

Abstract

Heap spraying is probably the most simple and effective memory corruption attack, which fills the memory with malicious payloads and then jumps at a random location in hopes of starting the attacker's routines. To counter this threat, GRAFFITI has been recently proposed as the first OS-agnostic framework for monitoring memory allocations of arbitrary applications at runtime; however, the main contributions of GRAFFITI are on the monitoring system, and its detection engine only considers simple heuristics which are tailored to certain attack vectors and are easily evaded. In this article, we aim to overcome this limitation and propose GLYPH as the first ML-based heap spraying detection system, which is designed to be effective, efficient, and resilient to evasive attackers. GLYPH relies on the information monitored by GRAFFITI, and we investigate the effectiveness of different feature spaces based on information entropy and memory n-grams, and discuss the several engineering challenges we have faced to make GLYPH efficient with an overhead compatible with that of GRAFFITI. To evaluate GLYPH, we build a representative dataset with several variants of heap spraying attacks, and assess GLYPH's resilience against evasive attackers through selective hold-out experiments. Results show that GLYPH achieves high accuracy in detecting spraying and is able to generalize well, outperforming the state-of-the-art approach for heap spraying detection, NOZZLE. Finally, we thoroughly discuss the trade-offs between detection performance and runtime overhead of GLYPH's different configurations.

Year: 2020 | Pages: 740 - 755

ISSN: 1556-6013 | DOI: 10.1109/TIFS.2020.3017925

Abstract

This article describes both a concept and an implementation of vehicle safe-mode (VSM) - a mechanism that may help reduce the damage of an identified cyberattack to the vehicle, its driver, the passengers, and its surroundings. Unlike other defense mechanisms that try to block the attack or simply notify of its existence, the VSM mechanism responds to a detected intrusion by limiting the vehicle’s functionality to safe operations and optionally activating additional security countermeasures. This is done by adopting ideas from the existing mechanism of Limp-mode that was originally designed to limit the damage of a mechanical, or an electrical, malfunction and let the vehicle “limp back home” in safety. Like Limp-mode, the purpose of safe-mode is to limit the vehicle from performing certain functions when conditions arise that could render full operation dangerous: Detecting a malfunction in the Limp-mode case is analogous to detecting an active cybersecurity breach in the safe-mode case, and the reactions should be analogous as well. The authors demonstrate that the VSM can be implemented, possibly even as an aftermarket add-on: to do so the authors developed a proof-of-concept (PoC) system and actively tested it in real time on an operating vehicle. Once activated, the authors' VSM system restricts the vehicle to Limp-mode behavior by guiding it to remain in low gear, taking into account the vehicle’s speed and the driver’s actions. The authors' system does not require any changes to the electronic control units (ECUs), or to any other part of the vehicle, beyond connecting the safe-mode manager (SMManager) to the correct bus. The authors note that their system can rely upon any deployed anomaly-detection system to identify the potential attack. The authors point out that restricting the vehicle to Limp-mode-like behavior by an aftermarket system is just an example. If a car manufacturer would integrate such a system into a vehicle, they would have many more options, and the resulting system would probably be safer and with a better human-machine interface.

Year: 2020 | Pages: 19 - 39

ISSN: 2572-1046 | DOI: 10.4271/11-02-02-0006

Abstract

Machine learning algorithms are effective in several applications, but they are not as much successful when applied to intrusion detection in cyber security. Due to the high sensitivity to their training data, cyber detectors based on machine learning are vulnerable to targeted adversarial attacks that involve the perturbation of initial samples. Existing defenses assume unrealistic scenarios; their results are underwhelming in non-adversarial settings; or they can be applied only to machine learning algorithms that perform poorly for cyber security. We present an original methodology for countering adversarial perturbations targeting intrusion detection systems based on random forests. As a practical application, we integrate the proposed defense method in a cyber detector analyzing network traffic. The experimental results on millions of labelled network flows show that the new detector has a twofold value: it outperforms state-of-the-art detectors that are subject to adversarial attacks; it exhibits robust results both in adversarial and non-adversarial scenarios.

Year: 2020 | Pages: 427 - 439

ISSN: 2471-285X | DOI: 10.1109/TETCI.2019.2961157

Abstract

Adversarial attacks represent a critical issue that prevents the reliable integration of machine learning methods into cyber defense systems. Past work has shown that even proficient detectors are highly affected just by small perturbations to malicious samples, and that existing countermeasures are immature. We address this problem by presenting AppCon, an original approach to harden intrusion detectors against adversarial evasion attacks. Our proposal leverages the integration of ensemble learning to realistic network environments, by combining layers of detectors devoted to monitor the behavior of the applications employed by the organization. Our proposal is validated through extensive experiments performed in heterogeneous network settings simulating botnet detection scenarios, and consider detectors based on distinct machine-and deep-learning algorithms. The results demonstrate the effectiveness of AppCon in mitigating the dangerous threat of adversarial attacks in over 75% of the considered evasion attempts, while not being affected by the limitations of existing countermeasures, such as performance degradation in non-adversarial settings. For these reasons, our proposal represents a valuable contribution to the development of more secure cyber defense platforms.

Year: 2020 | Pages: 653 - 676

ISSN: 2073-8994 | DOI: 10.3390/SYM12040653

Abstract

This paper proposes a novel approach for the evaluation of the performance achieved by trainees involved in cyber security exercises implemented in modern cyber ranges. Our main contributions include: the definition of a distributed monitoring architecture for gathering relevant information about trainees activities; an algorithm for modeling the trainee activities using directed graphs; novel scoring algorithms, based on graph operations, that evaluate different aspects (speed, precision) of a trainee during an exercise. With respect to previous work, our proposal allows to measure exactly how fast a user is progressing towards an objective and where he does wrong. We highlight that this is currently not possible in the most popular cyber ranges.

Year: 2020 | Pages: 236 - 247

ISSN: 1383-469X | DOI: 10.1007/s11036-019-01442-0

Abstract

Several advanced cyber attacks adopt the technique of "pivoting" through which attackers create a command propagation tunnel through two or more hosts in order to reach their final target. Identifying such malicious activities is one of the most tough research problems because of several challenges: command propagation is a rare event that cannot be detected through signatures, the huge amount of internal communications facilitates attackers evasion, timely pivoting discovery is computationally demanding. This paper describes the first pivoting detection algorithm that is based on network flows analyses, does not rely on any a-priori assumption on protocols and hosts, and leverages an original problem formalization in terms of temporal graph analytics. We also introduce a prioritization algorithm that ranks the detected paths on the basis of a threat score thus letting security analysts investigate just the most suspicious pivoting tunnels. Feasibility and effectiveness of our proposal are assessed through a broad set of experiments that demonstrate its higher accuracy and performance against related algorithms.

Year: 2020 | Pages: 404 - 415

ISSN: 2168-6750 | DOI: 10.1109/TETC.2017.2764885

Abstract

Security analytics and forensics applied to in-vehicle networks are growing research areas that gained relevance after recent reports of cyber-attacks against unmodified licensed vehicles. However, the application of security analytics algorithms and tools to the automotive domain is hindered by the lack of public specifications about proprietary data exchanged over in-vehicle networks. Since the controller area network (CAN) bus is the de-facto standard for the interconnection of automotive electronic control units, the lack of public specifications for CAN messages is a key issue. This paper strives to solve this problem by proposing READ: A novel algorithm for the automatic Reverse Engineering of Automotive Data frames. READ has been designed to analyze traffic traces containing unknown CAN bus messages in order to automatically identify and label different types of signals encoded in the payload of their data frames. Experimental results based on CAN traffic gathered from a licensed unmodified vehicle and validated against its complete formal specifications demonstrate that the proposed algorithm can extract and classify more than twice the signals with respect to the previous related work. Moreover, the execution time of signal extraction and classification is reduced by two orders of magnitude. Applications of READ to CAN messages generated by real vehicles demonstrate its usefulness in the analysis of CAN traffic.

Year: 2019 | Pages: 1083 - 1097

ISSN: 1556-6013 | DOI: 10.1109/TIFS.2018.2870826

Abstract

Designing secure, scalable, and resilient IoT networks is a challenging task because of resource-constrained devices and no guarantees of reliable network connectivity. Fog computing improves the resiliency of IoT, but its security model assumes that fog nodes are fully trusted. We relax this latter constraint by proposing a solution that guarantees confidentiality of messages exchanged through semi-honest fog nodes thanks to a lightweight proxy re-encryption scheme. We demonstrate the feasibility of the solution by applying it to IoT networks of low-power devices through experiments on microcontrollers and ARM-based architectures.

Year: 2019 | Pages: 1 - 21

ISSN: 1533-5399 | DOI: 10.1145/3284554

Abstract

Cloud database services represent a great opportunity for companies and organizations in terms of management and cost savings. However, outsourcing private data to external providers leads to risks of confidentiality and integrity violations. We propose an original solution based on encrypted Bloom filters that addresses the latter problem by allowing a cloud service user to detect unauthorized modifications to his outsourced data. Moreover, we propose an original analytical model that can be used to minimize storage and network overhead depending on the database structure and workload. We assess the effectiveness of the proposal as well as its performance improvements with respect to existing solutions by evaluating storage and network costs through micro-benchmarks and the TPC-C workload standard.

Year: 2018 | Pages: 497 - 515

ISSN: 0020-0255 | DOI: 10.1016/j.ins.2017.09.033

Abstract

Advanced Persistent Threats (APTs) are the most critical menaces to modern organizations and the most challenging attacks to detect. They span over long periods of time, use encrypted connections and mimic normal behaviors in order to evade detection based on traditional defensive solutions. We propose an innovative approach that is able to analyze efficiently high volumes of network traffic to reveal weak signals related to data exfiltrations and other suspect APT activities. The final result is a ranking of the most suspicious internal hosts; this rank allows security specialists to focus their analyses on a small set of hosts out of the thousands of machines that typically characterize large organizations. Experimental evaluations in a network environment consisting of about 10K hosts show the feasibility and effectiveness of the proposed approach. Our proposal based on security analytics paves the way to novel forms of automatic defense aimed at early detection of APTs in large and continuously varying networked systems.

Year: 2016 | Pages: 127 - 141

ISSN: 1389-1286 | DOI: 10.1016/j.comnet.2016.05.018

Abstract

The huge number of alerts generated by network-based defense systems prevents detailed manual inspections of security events. Existing proposals for automatic alerts analysis work well in relatively stable and homogeneous environments, but in modern networks, that are characterized by extremely complex and dynamic behaviors, understanding which approaches can be effective requires exploratory data analysis and descriptive modeling. We propose a novel framework for automatically investigating temporal trends and patterns of security alerts with the goal of understanding whether and which anomaly detection approaches can be adopted for identifying relevant security events. Several examples referring to a real large network show that, despite the high intrinsic dynamism of the system, the proposed framework is able to extract relevant descriptive statistics that allow to determine the effectiveness of popular anomaly detection approaches on different alerts groups.

Year: 2016 | Pages: 28 - 49

ISSN: 0167-4048 | DOI: 10.1016/j.cose.2015.10.003

Abstract

Abstract Mobile devices are becoming the most popular way of connection, but protocols supporting mobility represent a serious source of concerns because their initial design did not enforce strong security. This paper introduces a novel class of stealth network attacks, called mobility-based evasion, where an attacker splits a malicious payload in such a way that no part can be recognized by existing defensive mechanisms including the most modern network intrusion detection systems operating in stateful mode. We propose an original cooperative framework for intrusion detection that can prevent mobility-based evasion. The viability and performance of the proposed solution is shown through a prototype applied to Mobile IPv4, Mobile IPv6 and WiFi protocols.

Year: 2015 | Pages: 179 - 192

ISSN: 0020-0255 | DOI: 10.1016/j.ins.2015.03.025

Abstract

The success of the cloud database paradigm is strictly related to strong guarantees in terms of service availability, scalability and security, but also of data confidentiality. Any cloud provider assures the security and availability of its platform, while the implementation of scalable solutions to guarantee confidentiality of the information stored in cloud databases is an open problem left to the tenant. Existing solutions address some preliminary issues through SQL operations on encrypted data. We propose the first complete architecture that combines data encryption, key management, authentication and authorization solutions, and that addresses the issues related to typical threat scenarios for cloud database services. Formal models describe the proposed solutions for enforcing access control and for guaranteeing confidentiality of data and metadata. Experimental evaluations based on standard benchmarks and real Internet scenarios show that the proposed architecture satisfies also scalability and performance requirements.

Year: 2014 | Pages: 448 - 458

ISSN: 2168-7161 | DOI: 10.1109/TCC.2014.2378782

Abstract

The cloud database as a service is a novel paradigm that can support several Internet-based applications, but its adoption requires the solution of information confidentiality problems. We propose a novel architecture for adaptive encryption of public cloud databases that offers an interesting alternative to the trade-off between the required data confidentiality level and the flexibility of the cloud database structures at design time. We demonstrate the feasibility and performance of the proposed solution through a software prototype. Moreover, we propose an original cost model that is oriented to the evaluation of cloud database services in plain and encrypted instances and that takes into account the variability of cloud prices and tenant workload during a medium-term period.

Year: 2014 | Pages: 10 - 25

ISSN: 2168-7161 | DOI: 10.1109/TCC.2014.2314644

Abstract

Placing critical data in the hands of a cloud provider should come with the guarantee of security and availability for data at rest, in motion, and in use. Several alternatives exist for storage services, while data confidentiality solutions for the database as a service paradigm are still immature. We propose a novel architecture that integrates cloud database services with data confidentiality and the possibility of executing concurrent operations on encrypted data. This is the first solution supporting geographically distributed clients to connect directly to an encrypted cloud database, and to execute concurrent and independent operations including those modifying the database structure. The proposed architecture has the further advantage of eliminating intermediate proxies that limit the elasticity, availability, and scalability properties that are intrinsic in cloud-based solutions. The efficacy of the proposed architecture is evaluated through theoretical analyses and extensive experimental results based on a prototype implementation subject to the TPC-C standard benchmark for different numbers of clients and network latencies.

Year: 2014 | Pages: 437 - 446

ISSN: 1045-9219 | DOI: 10.1109/TPDS.2013.154

Abstract

Cyber attacks are becoming increasingly complex, especially when the target is a modern IT infrastructure, characterized by a layered architecture that integrates several security technologies such as firewalls and intrusion detection systems. These contexts can be violated by a multistep attack, that is a complex attack strategy that comprises multiple correlated intrusion activities. While a modern Intrusion Detection System detects single intrusions, it is unable to link them together and to highlight the strategy that underlies a multistep attack.Hence, a single multistep attack may generate a high number of uncorrelated intrusion alerts. The critical task of analyzing and correlating all these alerts is then performed manually by security experts. This process is time consuming and prone to human errors. This paper proposes a novel framework for the analysis and correlation of security alerts generated by state-of-the-art Intrusion Detection Systems. Our goal is to help security analysts in recognizing and correlating intrusion activities that are part of the same multistep attack scenario. The proposed framework produces correlation graphs, in which all the intrusion alerts that are part of the same multistep attack are linked together. By looking at these correlation graphs, a security analyst can quickly identify the relationships that link together seemingly uncorrelated intrusion alerts, and can easily recognize complex attack strategies and identify their final targets. Moreover, the proposed framework is able to leverage multiple algorithms for alert correlation.

Year: 2011 | Pages: 73 - 92

ISSN: 1738-9976 | DOI: n/a

Abstract

This paper proposes SixPack v2, an enhanced version of the SixPack attack that allows to evade even state-of-the-art misbehavior detection systems. As the original SixPack, SixPack v2 is a dynamic attack targeting other C-ITS entities by simulating the sudden activation of the braking system with consequent activation of the Anti-lock Braking System. SixPack v2 achieves better evasion by improving the main phases of the attack (FakeBrake, Recovery, and Rejoin) through a novel path-reconstruction algorithm that generates a more realistic representation of the real vehicle trajectory. We experimentally evaluate the evasion capabilities of SixPack v2 using the F2MD framework on the LuSTMini city scenario, and we compared the detection performance of the F2MD framework on both versions of SixPack. Results show that SixPack v2 evades detection with a significantly higher likelihood with respect to the initial version of the attack, even against the latest version of F2MD.

Year: 2022 | Pages: 243 - 249

ISBN: 979-8-3503-9730-7 | DOI: 10.1109/NCA57778.2022.10013565

Abstract

The rise of sequential Machine Learning (ML) methods has paved the way for a new generation of Network Intrusion Detection Systems (NIDS) which base their classification on the temporal patterns exhibited by malicious traffic. Previous work presents successful algorithms in this field, but just a few attempts try to assess their robustness in real-world contexts. In this paper, we aim to fill this gap by presenting a novel evaluation methodology. In particular, we propose a new time-based adversarial attack in which we simulate a delay in the malicious communications that changes the arrangement of the samples in the test set. Moreover, we design an innovative evaluation technique simulating a worst-case training scenario in which the last portion of the training set does not include any malicious flow. Through them, we can evaluate how much sequential ML-based NIDS are sensible to modifications that an adaptive attacker might apply at temporal level, and we can verify their robustness to the unpredictable traffic produced by modern networks. Our experimental campaign validates our proposal against a recent NIDS trained on a public dataset for botnet detection. The results demonstrate its high resistance to temporal adversarial attacks, but also a drastic performance drop when even just 1% of benign flows are injected at the end of the training set. Our findings raise questions about the reliable deployment of sequential ML-NIDS in practice, and at the same time can guide researchers to develop more robust defensive tools in the future.

Year: 2022 | Pages: 235 - 242

ISBN: 979-8-3503-9730-7 | DOI: 10.1109/NCA57778.2022.10013643

Abstract

This paper presents a comparative analysis of different Machine Learning-based detection algorithms designed for Controller Area Network (CAN) communication on three different datasets. This work focuses on addressing the current limitations of related scientific literature, related to the quality of the publicly available datasets and to the lack of public implementations of the detection solutions presented in literature. Since these issues are preventing the reproducibility of published results and their comparison with novel detection solutions, we remark that it is necessary that all security researchers working in this field start to address them properly to advance the current state-of-the-art in CAN intrusion detection systems. This paper strives to solve these issues by presenting a comparison of existing works on publicly available datasets.

Year: 2022 | Pages: 81 - 88

ISBN: 979-8-3503-9730-7 | DOI: 10.1109/NCA57778.2022.10013527

Abstract

None

Year: 2021 | Pages: 1 - 5

ISBN: 9781665495509 | DOI: 10.1109/NCA53618.2021.9685713

Abstract

The transportation sector is undergoing rapid changes to reduce pollution and increase life quality in urban areas. One of the most effective approaches is flexible car rental and sharing to reduce traffic congestion and parking space issues. In this paper, we envision a flexible car sharing framework where vehicle owners want to make their vehicles available for flexible rental to other users. The owners delegate the management of their vehicles to intermediate services under certain policies, such as municipalities or authorized services, which manage the due infrastructure and services that can be accessed by users. We investigate the design of an accountable solution that allow vehicles owners, who want to share their vehicles securely under certain usage policies, to control that delegated services and users comply with the policies. While monitoring users behavior, our approach also takes care of users privacy, preventing tracking or profiling procedures by other parties. Existing approaches put high trust assumptions on users and third parties, do not consider users' privacy requirements, or have limitations in terms of flexibility or applicability. We propose an accountable protocol that extends standard delegated authorizations and integrate it with Security Credential Management Systems (SCMS), while considering the requirements and constraints of vehicular networks. We show that the proposed approach represents a practical approach to guarantee accountability in realistic scenarios with acceptable overhead.

Year: 2021 | Pages: 1 - 7

ISBN: 9781665495509 | DOI: 10.1109/NCA53618.2021.9685942

Abstract

This paper presents SixPack, a cyber attack to VANET communications that is able to go undetected by the current state-of-the-art anomaly detectors. The SixPack attack is a dynamic attack conducted by an insider attacker who modifies the content of the Basic Safety Messages to pretend a sudden activation of the braking system with the consequent activation of the Anti-lock Braking System, and create a fake representation of the vehicle. The attacker then rejoins the fake representation of the vehicle with the real one, avoiding the current state-of-the-art anomaly detectors. We experimentally evaluated the evasion capabilities of the SixPack attack using the F2MD test framework on the LuST and LuSTMini city scenarios, demonstrating the ability of the attacker to generate a high percentage of false positives that prevent the attack from being detected consistently.

Year: 2021 | Pages: 1 - 6

ISSN: 1550-2252 | DOI: 10.1109/VTC2021-Spring51267.2021.9448656

Abstract

Cyber risks associated with modern cars are often referred to safety. However, modern cars expose a variety of digital services and process a variety of personal data, at least of the driver's. This paper unfolds the argument that car (cyber-)security and drivers' privacy are worthy of additional consideration, and does so by advancing “COSCA”, a framework for “COnceptualising Secure CArs” as interconnected nodes of the Next Generation Internet. COSCA adopts an innovative socio-technical approach. It crowdsources drivers' perceptions on core privacy topics and it classifies the data collected by cars and processed by manufacturers pursuant the General Data Protection Regulation. These steps inform a risk assessment which highlights the more relevant mitigation strategies and cyber security technologies. Finally, COSCA aims at designing novel interfaces to enable drivers to exercise their rights about personal data collection and processing.

Year: 2021 | Pages: 37 - 46

ISSN: 1617-5468 | DOI: n/a

Abstract

Emerging Cooperative Intelligent Transportation Systems (C-ITS) enable improved driving experience and safety guarantees, but require secure Vehicular Ad-hoc NETworks (VANETs) that must comply to strict performance constraints. Specialized standards have been defined to these aims, such as the IEEE 1609.2 that uses network-efficient cryptographic protocols to reduce communication latencies. The reduced latencies are achieved through a combination of the Elliptic Curve Qu-Vantstone (ECQV) implicit certificate scheme and the Elliptic Curve Digital Signature Algorithm (ECDSA), to guarantee data integrity and authenticity. However, literature lacks implementations and evaluations for vehicular systems. In this paper, we consider the IEEE 1609.2 standard for secure VANETs and investigate the feasibility of ECQV and ECDSA schemes when deployed in C-ITSs. We propose a prototype implementation of the standard ECQV scheme to evaluate its performance on automotive-grade hardware. To the best of our knowledge, this is the first open implementation of the scheme for constrained devices that are characterized by low computational power and low memory. We evaluate its performance against C-ITS communication latency constraints and show that, although even highly constrained devices can support the standard, complying with stricter requirements demands for higher computational resources.

Year: 2020 | Pages: 1 - 6

ISSN: 1550-2252 | DOI: 10.1109/VTC2020-Fall49728.2020.9348712

Abstract

None

Year: 2019 | Pages: 1 - 1

DOI: 10.1109/NCA.2019.8935054

Abstract

None

Year: 2019 | Pages: n/a - n/a

DOI: n/a

Abstract

Recent cyber-attacks to real vehicles demonstrated the risks related to connected vehicles, and spawned several research effort aimed at proposing algorithms and architectural solutions to improve the security of these vehicles. Most of the documented attacks to the connected vehicles require the injection of maliciously forged messages to subvert the normal behaviour of the electronic microcontrollers. More recently, researchers discovered that by abusing error isolation mechanisms of the Controller Area Network (CAN), one of the protocols deployed for in-vehicle networking, it is possible to isolate a microcontroller from the vehicle internal network (namely bus-off attack), with possible severe implication on both safety and security. This vulnerability has already been exploited for gaining remote control of a vehicle, by driving a targeted microcontroller in bus-off and impersonating it through the injection of malicious messages on the CAN bus. This paper strives to counter bus-off attacks by proposing an algorithm for the detection of missing messages from the in- vehicle CAN bus. Bus-off attacks to in-vehicle network are simulated by removing messages from valid CAN traces recorded from an unmodified licensed vehicle. Experimental evaluations of our proposal and comparisons with previous work demonstrate that the proposed algorithms outperforms other detection algorithms, achieving almost perfect detection (F-score equal or near to 1.0) across different tests.

Year: 2019 | Pages: 1 - 7

DOI: 10.1109/VTCFall.2019.8891068

Abstract

None

Year: 2019 | Pages: 1 - 18

ISBN: 978-9949-9904-5-0 | DOI: 10.23919/CYCON.2019.8756865

Abstract

None

Year: 2018 | Pages: xxx - n/a

DOI: 10.1109/SMARTCOMP.2018.00016

Abstract

None

Year: 2018 | Pages: 1 - 1

DOI: 10.1109/NCA.2018.8548342

Abstract

The concordant vision of the future automotive landscape foresees vehicles that are always connected to infrastructure and Cloud services, and that are equipped with autonomous driving or advanced driver assistance systems. It is clear that in a similar scenario cybersecurity of modern and future vehicles is paramount. With connected autonomous vehicles the protection from external attack will be an essential requirement, motivated by the outstanding safety implications of an autonomous vehicles remotely controlled by an attacker or a malware. However, the automotive industry still lacks reliable and repeatable methods to assess the cybersecurity level of modern cars. This paper has a twofold contribution. First, it describes the ongoing effort of regulatory bodies within the European Union toward the definition of cybersecurity certification schemes. Second, it outlines the main requirements of a cybersecurity ranking approach that is suitable for certifying the security level of connected vehicles. Since improved cybersecurity guarantees will come at the expense of increased complexity and costs, the proposed ranking approach allows to assess whether the cybersecurity level is appropriate by considering the potential safety risks of a successful attack to the ranked system or subsystem.

Year: 2018 | Pages: 1 - 6

ISBN: 978-8-8872-3738-2 | DOI: 10.23919/EETA.2018.8493180

Abstract

None

Year: 2018 | Pages: 371 - 389

ISBN: 978-9-9499-9042-9; 978-9-9499-9043-6 | DOI: 10.23919/CYCON.2018.8405026

Abstract

Modern vehicles are complex cyber physical systems where communication protocols designed for physically isolated networks are now employed to connect Internet-enabled devices. This unforeseen increase in connectivity creates novel attack surfaces, and exposes safety-critical functions of the vehicle to cyber attacks. As standard security solutions are not applicable to vehicles due to resource constraints and compatibility issues, research is proposing tailored approaches to cope with existing systems and to design next generations vehicles. In this paper we focus on solutions based on cryptographic protocols to protect in-vehicle communications and prevent unauthorized manipulation of the vehicle behaviors. Existing proposals consider vehicles as monolithic systems and evaluate performance and costs of the proposed solutions without considering the complex life-cycle of automotive components and the multifaceted automotive ecosystem that includes a large number of actors. The main contribution of this paper is a study of the impact of security solutions by considering vehicles life-cycle. We model existing proposals and highlight their impacts on vehicles production and maintenance operations by taking into consideration interactions among multiple players. Finally, we give insights on the requirements of architectures for secure intra-vehicular protocols.

Year: 2018 | Pages: 452 - 457

ISBN: 9781538647059 | DOI: 10.1109/SMARTCOMP.2018.00045

Abstract

This paper describes a concept for vehicle safe-mode, that may help reduce the potential damage of an identified cyber-attack. Unlike other defense mechanisms, that try to block the attack or simply notify of its existence, our mechanism responds to the detected breach, by limiting the vehicle’s functionality to relatively safe operations, and optionally activating additional security counter-measures. This is done by adopting the already existing mechanism of Limp-mode, that was originally designed to limit the potential damage of either a mechanical or an electrical malfunction and let the vehicle “limp back home” in relative safety. We further introduce two modes of safe-modemoperation: In Transparent-mode, when a cyber-attack is detected the vehicle enters its pre-configured Limp-mode; In Extended-mode we suggest to use custom messages that offer additional flexibility to both the reaction and the recovery plans. While Extended-mode requires modifications to the participating ECUs, Transparent-mode may be applicable to existing vehicles since it does not require any changes in the vehicle’s systems—in other words, it may even be deployed as an external component connected through the OBD-II port. We suggest an architectural design for the given modes, and include guidelines for a safe-mode manager, its clients, possible reactions, and recovery plans. We note that our system can rely upon any deployed anomaly-detection system to identify the potential attack.

Year: 2017 | Pages: n/a - n/a

DOI: n/a

Abstract

After many research efforts, Network Intrusion Detection Systems still have much room for improvement. This paper proposes a novel method for automatic and timely analysis of traffic generated by large networks, which is able to identify malicious external hosts even if their activities do not raise any alert by existing defensive systems. Our proposal focuses on periodic communications, since our experimental evaluation shows that they are more related to malicious activities, and it can be easily integrated with other detection systems. We highlight that periodic network activities can occur at very different intervals ranging from seconds to hours, hence a timely analysis of long time-windows of the traffic generated by large organizations is a challenging task in itself. Existing work is primarily focused on identifying botnets, whereas the method proposed in this paper has a broader target and aims to detect external hosts that are likely involved in any malicious operation. Since malware-related network activities can be considered as rare events in the overall traffic, the output of the proposed method is a manageable graylist of external hosts that are characterized by a considerably higher likelihood of being malicious compared to the entire set of external hosts contacted by the monitored large network. A thorough evaluation on a real large network traffic demonstrates the effectiveness of our proposal, which is capable of automatically selecting only dozens of suspicious hosts from hundreds of thousands, thus allowing security operators to focus their analyses on few likely malicious targets.

Year: 2017 | Pages: 1 - 8

ISBN: 9781538614655; 9781538614648 | DOI: 10.1109/NCA.2017.8171326

Abstract

Analysis of in-vehicle networks is an open research area that gained relevance after recent reports of cyber attacks against connected vehicles. After those attacks gained international media attention, many security researchers started to propose different algorithms that are capable to model the normal behaviour of the CAN bus to detect the injection of malicious messages. However, despite the automotive area has different constraint than classical IT security, many security research have been conducted by applying sophisticated algorithm used in IT anomaly detection, thus proposing solutions that are not applicable on current Electronic Control Units (ECUs). This paper proposes a novel intrusion detection algorithm that aims to identify malicious CAN messages injected by attackers in the CAN bus of modern vehicles. Moreover, the proposed algorithm has been designed and implemented with the very strict constraint of low-end ECUs, having low computational complexity and small memory footprints. The proposed algorithm identifies anomalies in the sequence of the payloads of different classes of IDs by computing the Hamming distance between consecutive payloads. Its detection performance are evaluated through experiments carried out using real CAN traffic gathered from an unmodified licensed vehicle.

Year: 2017 | Pages: 1 - 6

ISBN: 9788887237375 | DOI: n/a

Abstract

This paper proposes an innovative framework for the early detection of several cyber attacks, where the main component is an analytics core that gathers streams of raw data generated by network probes, builds several layer models representing different activities of internal hosts, analyzes intra-layer and inter-layer information. The online analysis of internal network activities at different levels distinguishes our approach with respect to most detection tools and algorithms focusing on separate network levels or interactions between internal and external hosts. Moreover, the integrated multi-layer analysis carried out through parallel processing reduces false positives and guarantees scalability with respect to the size of the network and the number of layers. As a further contribution, the proposed framework executes autonomous triage by assigning a risk score to each internal host. This key feature allows security experts to focus their attention on the few hosts with higher scores rather than wasting time on thousands of daily alerts and false alarms.

Year: 2017 | Pages: 1 - 18

ISBN: 9789949990405 | DOI: 10.23919/CYCON.2017.8240337

Abstract

Delegated authorization protocols have become wide-spread to implement Web applications and services, where some popular providers managing people identity information and personal data allow their users to delegate third party Web services to access their data. In this paper, we analyze the risks related to untrusted providers not behaving correctly, and we solve this problem by proposing the first verifiable delegated authorization protocol that allows third party services to verify the correctness of users data returned by the provider. The contribution of the paper is twofold: we show how delegated authorization can be cryptographically enforced through authenticated data structures protocols, we extend the standard OAuth2 protocol by supporting efficient and verifiable delegated authorization including database updates and privileges revocation.

Year: 2017 | Pages: 718 - 723

ISSN: 0730-3157 | DOI: 10.1109/COMPSAC.2017.260

Abstract

This paper proposes a novel intrusion detection algorithm that aims to identify malicious CAN messages injected by attackers in the CAN bus of modern vehicles. The proposed algorithm identifies anomalies in the sequence of messages that flow in the CAN bus and is characterized by small memory and computational footprints, that make it applicable to current ECUs. Its detection performance are demonstrated through experiments carried out on real CAN traffic gathered from an unmodified licensed vehicle.

Year: 2017 | Pages: 1577 - 1583

ISBN: 9781509048045 | DOI: 10.1109/IVS.2017.7995934

Abstract

This paper proposes an efficient protocol for verifiable delegation of computation over outsourced set collections. It improves state of the art protocols by using asymmetric bilinear pairing settings for improved performance with respect to previous proposals based on symmetric settings. Moreover, it extends update operations by supporting efficient modifications over multiple sets. With respect to previous work the proposed protocol has a modular design, that clearly identifies its main building blocks and well-defined interfaces among them. This novel conceptualization allows easier auditing of the protocol security properties and serves as the blueprint of a novel implementation that is released publicly (https://weblab.ing.unimore.it/people/ferretti/versop/). To the best of our knowledge, this is the first public implementation of a protocol for verifiable sets operations.

Year: 2016 | Pages: 626 - 636

ISSN: 0302-9743 | DOI: 10.1007/978-3-319-48965-0_41

Abstract

This paper evaluates the effectiveness of information-theoretic anomaly detection algorithms applied to networks included in modern vehicles. In particular, we focus on providing an experimental evaluation of anomaly detectors based on entropy. Attacks to in-vehicle networks were simulated by injecting different classes of forged CAN messages in traces captured from a modern licensed vehicle. Experimental results show that if entropy-based anomaly detection is applied to all CAN messages it is only possible to detect attacks that comprise a high volume of forged CAN messages. On the other hand, attacks characterized by the injection of few forged CAN messages attacks can be detected only by applying several independent instances of the entropy based anomaly detector, one for each class of CAN messages.

Year: 2016 | Pages: 429 - 434

ISBN: 9781509011315 | DOI: 10.1109/RTSI.2016.7740627

Abstract

Advanced Persistent Threats (APTs) represent the most challenging threats to the security and safety of the cyber landscape. APTs are human-driven attacks backed by complex strategies that combine multidisciplinary skills in information technology, intelligence, and psychology. Defending large organisations with tens of thousands of hosts requires similar multi-factor approaches. We propose a novel framework that combines different techniques based on big data analytics and security intelligence to support human analysts in prioritising the hosts that are most likely to be compromised. We show that the collection and integration of internal and external indicators represents a step forward with respect to the state of the art in the field of early detection and mitigation of APT activities.

Year: 2016 | Pages: 243 - 261

DOI: n/a

Abstract

The adoption of public cloud services, as well as other data outsourcing solutions, raises concerns about confidentiality and integrity of information managed by a third party. By focusing on data integrity, we propose a novel protocol that allows cloud customers to verify the correctness of results produced by key-value databases. The protocol is designed for supporting efficient insertion and retrieval of large sets of data through bulk operations in read and append-only workloads. In these contexts, the proposed protocol improves state-of-the-art by reducing network overheads thanks to an original combination of aggregate bilinear map signatures and extractable collision resistant hash functions.

Year: 2016 | Pages: 37 - 51

ISSN: 1611-3349 | DOI: 10.1007/978-3-319-41483-6_3

Abstract

The cloud computing paradigm has become really popular, and its adoption is constantly increasing. Hence, also network activities and security alerts related to cloud services are increasing and are likely to become even more relevant in the upcoming years. In this paper, we propose the first characterization of real security alerts related to cloud activities and generated by a network sensor at the edge of a large network environment over several months. Results show that the characteristics of cloud security alerts differ from those that are not related to cloud activities. Moreover, alerts related to different cloud providers exhibit peculiar and different behaviors that can be identified through temporal analyses. The methods and results proposed in this paper are useful as a basis for the design of novel algorithms for the automatic analysis of cloud security alerts, that can be aimed at forecasting, prioritization, anomaly and state-change detection.

Year: 2015 | Pages: 75 - 82

ISBN: 0769556035 | DOI: 10.1109/NCCA.2015.21

Abstract

Modern societies produce a huge amount of open source information that is often published on the Web in a natural language form. The impossibility of reading all these documents is paving the way to semantic-based technologies that are able to extract from unstructured documents relevant information for analysts. Most solutions extract uncorrelated pieces of information from individual documents; few of them create links among related documents and, to the best of our knowledge, no technology focuses on the time evolution of relations among entities. We propose a novel approach for managing, querying and visualizing temporal knowledge extracted from unstructured documents that can open the way to novel forms of sense-making and decision-making processes. We leverage state-of-the-art natural language processing engines for the semantic analysis of textual data sources to build a temporal graph database that highlights relationships among entities belonging to different documents and time frames. Moreover, we introduce the concept of temporal graph query that analysts can use to identify all the relationships of an entity and to visualize their evolution over time. This process enables the application of statistical algorithms that can be oriented to the automatic analysis of anomalies, state change detection, forecasting. Preliminary results demonstrate that the representation of the evolution of entities and relationships allows an analyst to highlight relevant events among the large amount of open source documents.

Year: 2015 | Pages: 185 - 202

ISBN: 9789949954421 | DOI: 10.1109/CYCON.2015.7158477

Abstract

Traditional computation outsourcing and modern cloud computing are affected by a common risk of distrust between service requestor and service provider. We propose a novel protocol, named Probus, that offers guarantees of correct behavior to both parts without assuming any trust relationship between them in the context of cloud-based key-value databases. Probus allows a service requestor to have evidence of cloud provider misbehavior on its data, and a cloud provider to defend itself from false accusations by demonstrating the correctness of its operations. Accusation and defense proofs are based on cryptographic mechanisms that can be verified by a third party. Probus improves the state-of-the-art by introducing novel solutions that allow for efficient verification of data security properties and by limiting the overhead required to provide its security guarantees. Thanks to Probus it is possible to check the correctness of all the results generated by a cloud service, thus improving weaker integrity assurance based on probabilistic verifications that are adopted by related work.

Year: 2015 | Pages: 157 - 164

ISBN: 9781467392990; 9781467392990 | DOI: 10.1109/CSCloud.2015.51

Abstract

Cloud services represent an unprecedented opportunity, but their adoption is hindered by confidentiality and integrity issues related to the risks of outsourcing private data to cloud providers. This paper focuses on integrity and proposes an innovative solution that allows cloud tenants to detect unauthorized modifications to outsourced data while minimizing storage and network overheads. Our approach is based on encrypted Bloom filters, and is designed to allow efficient integrity verification for databases stored in the cloud. We assess the effectiveness of the proposal as well as its performance improvements with respect to existing solutions by evaluating storage and network costs.

Year: 2014 | Pages: 1 - 6

ISBN: 9781479942763 | DOI: 10.1109/ISCC.2014.6912574

Abstract

Using cloud infrastructures to store and backup data is becoming a popular alternative that guarantees performance and scalability at reasonable prices. However, standard cloud solutions could raise some concerns about data confidentiality and dependency on a single provider. We aim to address these issues by using cloud storage of multiple cloud providers. Our solution ciphers, partitions and replicates data among multiple cloud architectures, thus augmenting availability and confidentiality, and avoiding lock-in of one cloud provider. The proposed model is implemented through open source software that leverages data storage offered by multiple providers. This prototype demonstrates the effectiveness of the geographically distributed architecture in several real case scenarios.

Year: 2013 | Pages: 201 - 207

ISBN: 978-1-61208-271-4 | DOI: n/a

Abstract

The users perception that the confidentiality of their data is endangered by internal and external attacks is limiting the diffusion of public cloud database services. In this context, the use of cryptography is complicated by high computational costs and restrictions on supported SQL operations over encrypted data. In this paper, we propose an architecture that takes advantage of adaptive encryption mechanisms to guarantee at runtime the best level of data confidentiality for any type of SQL operation. We demonstrate through a large set of experiments that these encryption schemes represent a feasible solution for achieving data confidentiality in public cloud databases, even from a performance point of view.

Year: 2013 | Pages: 36 - 42

ISBN: 9781612082981 | DOI: n/a

Abstract

The diffusion of cloud database services requires a lot of efforts to improve confidentiality of data stored in external infrastructures. We propose a novel scheme that integrates data encryption with users access control mechanisms. It can be used to guarantee confidentiality of data with respect to a public cloud infrastructure, and to minimize the risks of internal data leakage even in the worst case of a legitimate user colluding with some cloud provider personnel. The correctness and feasibility of the proposal is demonstrated through formal models, while the integration in a cloud-based architecture is left to future work.

Year: 2013 | Pages: 717 - 722

ISBN: 9780769550954 | DOI: 10.1109/CloudCom.2013.172

Abstract

Typical Cloud database services guarantee high availability and scalability, but they rise many concerns about data confidentiality. Combining encryption with SQL operations is a promising approach although it is characterized by many open issues. Existing proposals, which are based on some trusted intermediate server, limit availability and scalability of original cloud database services. We propose an alternative architecture that avoids any intermediary component, thus achieving availability and scalability comparable to that of unencrypted cloud database services. Moreover, our proposal guarantees data consistency in scenarios in which independent clients concurrently execute SQL queries, and the structure of the database can be modified.

Year: 2012 | Pages: 179 - 193

ISBN: 978-3-642-35361-1 | DOI: 10.1007/978-3-642-35362-8_15

Abstract

Attacks to information systems are becoming moresophisticated and traditional algorithms supporting NetworkIntrusion Detection Systems may be ineffective or cause toomany false alarms. This paper describes a new algorithm for thecorrelation of alerts generated by Network Intrusion DetectionSystems. It is specifically oriented to face multistep attacks wheremultiple intrusion activities belonging to the same attack scenarioare performed within a small time window. This algorithm takesas its input the security alerts generated by a NIDS and, througha pseudo-bayesian alert correlation, is able to identify those thatare likely to belong to the same multistep attack scenario. Theproposed approach is completely unsupervised and applicable tosecurity alerts generated by any kind of NIDS.

Year: 2011 | Pages: 15 - 20

ISBN: 9781457710346 | DOI: 10.1109/CSS.2011.6058565

Abstract

A growing trend in the cybersecurity landscape is repre-sented by multistep attacks that involve multiple correlated intrusionactivities to reach the intended target. The duty of correlating secu-rity alerts and reconstructing complete attack scenarios is left to sys-tem administrators because current Network Intrusion Detection Sys-tems (NIDS) are still oriented to generate alerts related to single attacks,with no or minimal correlation analysis among dierent security alerts.We propose a novel approach for the automatic analysis of multiple se-curity alerts generated by state-of-the-art signature-based NIDS. Ourproposal is able to group security alerts that are likely to belong to thesame attack scenario, and to identify correlations and causal relation-ships among them. This goal is achieved by combining alert classicationthrough Self Organizing Maps and unsupervised clustering algorithms.The ecacy of the proposal is demonstrated through a prototype testedagainst network trac traces containing multistep attacks.

Year: 2011 | Pages: 101 - 110

ISBN: 9783642231407 | DOI: 10.1007/978-3-642-23141-4_10

Abstract

This paper presents a novel NIDS evasion strategy that allows attackers to exploit network mobility to perform attacks undetectable by modern NIDSs. Mobility-based NIDS evasion works by combining traditional evasion techniques and node mobility. It represents a generally applicable evasion strategy that works on several protocols for node mobility, and it is effective against state-of-the- art and well configured signature-based NIDSs. We describe three evasion scenarios based on node mobility, and demonstrate the practical applicability of the proposed evasion strategy through a proof of concept attack in a realistic network environment. We conclude the paper by presenting some ideas addressing mobility-based NIDS evasion.

Year: 2011 | Pages: 1 - 6

ISBN: 9781424487059 | DOI: 10.1109/NTMS.2011.5721046

Abstract

The diffusion of mobile devices and technologies supportingtransparent network mobility can have detrimental effects onnetwork security. We describe how an attacker can leverage mobility in IPv6 networks to perpetrate known attackswhile evading detection by state-of-the-art Network IntrusionDetection Systems (NIDSs). We then propose a new defensestrategy based on the exchange of state information amongdistributed NIDSs. We demonstrate the effectiveness of the proposed solution through a prototype implementation, evaluatedexperimentally in a Mobile IPv6 network.

Year: 2011 | Pages: 1 - 9

ISBN: 9781457703522 | DOI: 10.1109/WoWMoM.2011.5986488

Abstract

The complexity of modern networked informationsystems, as well as all the defense-in-depth best practices,require distributed intrusion detection architectures relying onthe cooperation of multiple components. Similar solutions causea multiplication of alerts, thus increasing the time needed for alertmanagement and hiding the few critical alerts as needles in ahay stack. We propose an innovative distributed architecture forintrusion detection that is able to provide system administratorswith selective and early security warnings. This architecture issuitable to large networks composed by several departmentsbecause it leverages hierarchical and peer-to-peer cooperationschemes among distributed NIDSes. Moreover, it embeds adistributed alert ranking system that makes it possible to evaluatethe real level of risk represented by a security alert generatedby a NIDS, and it allows independent network departments toexchange early warnings about critical threats. Thanks to thesefeatures, a system administrator can focus on the few alertsthat represent a real threat for the controlled infrastructure andcan be notified about the most dangerous intrusions before hisdepartment is attacked.

Year: 2010 | Pages: 604 - 611

ISBN: 9781424475476 | DOI: 10.1109/CIT.2010.124

Abstract

The complexity of modern network architectures and the epidemic diffusion of malware require collaborative approaches for defense. We present a novel distributed system where each component collaborates to the intrusion and malware detection and to the dissemination of the local analyses. The proposed architecture is based on a decentralized, peer-to-peer and sensor-agnostic design that addresses dependability and load unbalance issues affecting existing systems based on centralized and hierarchical schemes. Load balancing properties, ability to tolerate churn, self-organization capabilities and scalability are demonstrated through a prototype integrating different open source defensive software.

Year: 2009 | Pages: 475 - 490

ISSN: 0302-9743 | DOI: 10.1007/978-3-642-04474-8_37

Abstract

Recent evidence of successful Internet-based attacks and frauds involving financial institutions highlights the inadequacy of the existing protection mechanisms, in which each instutition implements its own isolated monitoring and reaction strategy. Analyzing on-line activity and detecting attacks on a large scale is an open issue due to the huge amounts of events that should be collected and processed. In this paper, we propose a large-scale distributed event processing system, called intelligence cloud, allowing the financial entities to participate in a widely distributed monitoring and detection effort through the exchange and processing of information locally available at each participating site. We expect this approach to be able to handle large amounts of events arriving at high rates from multiple domains of the financial scenario. We describe a framework based on the intelligence cloud where each participant can receive early alerts enabling them to deploy proactive countermeasures and mitigation strategies.

Year: 2009 | Pages: 1 - 18

ISBN: 9781605585185 | DOI: 10.1145/1558607.1558628

Abstract

Data centers strive to provide reliable access to the data and services that they host. This reliable access requires the hosted data and services hosted by the data center to be both consistent and available. Byzantine fault tolerance (BFT) replication offers the promise of services that are consistent and available despite arbitrary failures by a bounded number of servers and an unbounded number of clients.

Year: 2009 | Pages: n/a - n/a

ISBN: 978160558-2962 | DOI: 10.1145/1529974.1529992

Abstract

This paper argues for a new approach to building Byzantine fault tolerant replication systems. We observe that although recently developed BFT state machine replication protocols are quite fast, they don't tolerate Byzantine faults very well: a single faulty client or server is capable of rendering PBFT, Q/U, HQ, and Zyzzyva virtually unusable. In this paper, we (1) demonstrate that existing protocols are dangerously fragile, (2) define a set of principles for constructing BFT services that remain useful even when Byzantine faults occur, and (3) apply these principles to construct a new protocol, Aardvark. Aardvark can achieve peak performance within 40% of that of the best existing protocol in our tests and provide a significant fraction of that performance when up to f servers and any number of clients are faulty. We observe useful throughputs between 11706 and 38667 requests per second for a broad range of injected faults.

Year: 2009 | Pages: n/a - n/a

ISBN: 9781931971676 | DOI: n/a

Abstract

The constant increase of malware threats clearly shows that the present countermeasures are not sufficient especially because most actions are put in place only when infections have already spread. In this paper, we present an innovative collaborative architecture for malware analysis that aims to early detection and timely deployment of countermeasures. The proposed system is a multi-tier architecture where the sensor nodes are geographically distributed over multiple organizations. These nodes send alerts to intermediate managers that, in their turn, communicate with one logical collector and analyzer. Relevant information, that is determined by the automatic analysis of the malware behavior in a sandbox, and countermeasures are sent to all the cooperating networks. There are many other novel features in the proposal. The architecture is extremely scalable and flexible because multiple levels of intermediate managers can be utilized depending on the complexity of the network of the participating organization. Cyphered communications among components help preventing the leakage of sensitive information and allow the pairwise authentication of the nodes involved in the information sharing. The feasibility of the proposed architecture is demonstrated through an operative prototype realized using open source software.

Year: 2008 | Pages: 79 - 93

ISBN: 9780387096988 | DOI: 10.1007/978-0-387-09699-5_6

Abstract

Network Intrusion Detection Systems (NIDS) are popular components for a fast detection of network attacks and intrusions, but their efficacy is limited by the high numbers of false alarms that affect them. As a consequence, system administrators,that have to manually manage an overwhelming amount of intrusion alerts, tend to decrease the alarm threshold or even to deactivate most NIDS functions. These weaknesses are frequently exploited by the attackers to avoid or to delay attackdetection.In order to improve the efficacy of attack detection and reduce the amount of false positives, we propose a novel scheme for runtime lert management. It filters innocuous attacks by taking advantage of the correlation between the NIDS alerts and detailed information concerning the protected information systems, that is retrieved from heterogeneous and unstructured data sources. Thanks to the proposed scheme, an alert is sent to the system administrator only if an attack threatens some real vulnerability of the protected hosts. Otherwise, as it occurs in the large majority of the cases, the alert is stored for a subsequent offline analysis. The viability and efficacy of the proposed solution are demonstrated through an operative prototype that has been tested in networks subject to realistic attacks.

Year: 2008 | Pages: 287 - 296

ISBN: 9781845641108 | DOI: 10.2495/DATA080271

Abstract

The Mobile IP (MIP) protocol that supports node mobility in IP networks may be implemented through two routing schemes: triangular routing and reverse tunneling. While triangular routing guarantees better performance because of shorter routing paths, it is not compatible with egress filtering policies enforced by many firewalls. As a result, it is necessary to recur to the slower reverse tunneling routing scheme that causes lower mobile connection throughput and higher round trip times. In this paper, we propose an innovative adaptive traffic filtering technique in which egress filtering rules are dynamically and automatically modified to reflect the presence of mobile nodes inside the protected network. The proposed scheme, called secure triangular routing, guarantees the best trade-off between performance and security because it enables triangular routing without violating network security policies. Viability and performance improvements of the proposed solution have been demonstrated by experiments carried out through a prototype. The proposed solution does not require any modification in correspondent nodes or in their networks, and it fully complies with the MIP protocol specifications.

Year: 2008 | Pages: 43 - 50

ISBN: 9781605582375 | DOI: 10.1145/1454586.1454594

Abstract

We present FlightPath, a novel peer-to-peer streaming application that provides a highly reliable data stream to a dynamic set of peers. We demonstrate that FlightPath reduces jitter compared to previous works by several orders of magnitude. Furthermore, FlightPath uses a number of run-time adaptations to maintain low jitter despite 10% of the population behaving maliciously and the remaining peers acting selfishly. At the core of FlightPath's success are approximate equilibria. These equilibria allow us to design incentives to limit selfish behavior rigorously, yet they provide sufficient flexibility to build practical systems. We show how to use an Ɛ-Nash equilibrium, instead of a strict Nash, to engineer a live streaming system that uses bandwidth efficiently, absorbs flash crowds, adapts to sudden peer departures, handles churn, and tolerates malicious activity.

Year: 2008 | Pages: n/a - n/a

ISBN: 9781931971652 | DOI: n/a

Abstract

A traditional Network Intrusion Detection System (NIDS) isbased on a centralized architecture that does not satisfy theneeds of most modern network infrastructures characterizedby high traffic volumes and complex topologies. The problemof decentralized NIDS based on multiple sensors is thateach of them gets just a partial view of the network trafficand this prevents a stateful and fully reliable traffic analysis.We propose a novel cooperation mechanism that addressesthe previous issues through an innovative state managementand state migration framework. It allows multipledecentralized sensors to share their internal state, thus accomplishing innovative and powerful traffic analysis. Theadvanced functionalities and performance of the proposedcooperative framework for network intrusion detection systemsare demonstrated through a fully operative prototype.

Year: 2007 | Pages: 165 - 174

ISBN: 9781595939456 | DOI: 10.1145/1323548.1323576

Abstract

Increasing traffic and the necessity of stateful analyses impose strong computational requirements on network intrusion detection systems (NIDS), and motivate the need of distributed architectures with multiple sensors. In a context of high traffic with heavy tailed characteristics, static rules for dispatching traffic slices among distributed sensors cause severe imbalance. Hence, the distributed NIDS architecture must be combined with adequate mechanisms for dynamic load redistribution.In this paper, we propose and compare different policies for the activation/deactivation of the dynamic load balancer. In particular, we consider and compare single vs. double threshold schemes, and load representations based on resource measures vs. load aggregation models.Our experimental results show that the best combination of a double threshold scheme with a linear aggregation of resource measures is able to achieve a really satisfactory balance of the sensor loads together with a sensible reduction of the number of load balancer activations.

Year: 2007 | Pages: 153 - 160

ISBN: 9780769529226 | DOI: 10.1109/NCA.2007.17

Abstract

Abstract—In a scenario where network bandwidth and traffic are continuously growing, network appliances that have to monitor and analyze all flowing packets are reaching their limits. These issues are critical especially for Network Intrusion Detection Systems (NIDS) that need to trace and reassemble every connection, and to examine every packet flowing on the monitored link(s), to guarantee high security levels. Any NIDS based on a single component cannot scale over certain thresholds, even if it has some parts built in hardware. Hence, parallel architectures appear as the most valuable alternative for the future. In this paper, we propose a parallel NIDS architecture that is able to provide us with fully reliable analysis, high performance and scalability. These properties come together with the low costs and high flexibility that are guaranteed by a total software implementation. The load balancing mechanism of the proposed NIDS distributes the traffic among a configurable number of parallel sensors, so that each of them is reached by a manageable amount of traffic. The parallelism and traffic distribution do not alter the results of the traffic analysis that remains reliable and stateful.

Year: 2006 | Pages: N/A - N/A

ISBN: 9783937201023 | DOI: n/a