79 research outputs found

    On the placement of security-related Virtualised Network Functions over data center networks

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    Middleboxes are typically hardware-accelerated appliances such as firewalls, proxies, WAN optimizers, and NATs that play an important role in service provisioning over today's data centers. Reports show that the number of middleboxes is on par with the number of routers, and consequently represent a significant commitment from an operator's capital and operational expenditure budgets. Over the past few years, software middleboxes known as Virtual Network Functions (VNFs) are replacing the hardware appliances to reduce cost, improve the flexibility of deployment, and allow for extending network functionality in short timescales. This dissertation aims at identifying the unique characteristics of security modules implementation as VNFs in virtualised environments. We focus on the placement of the security VNFs to minimise resource usage without violating the security imposed constraints as a challenge faced by operators today who want to increase the usable capacity of their infrastructures. The work presented here, focuses on the multi-tenant environment where customised security services are provided to tenants. The services are implemented as a software module deployed as a VNF collocated with network switches to reduce overhead. Furthermore, the thesis presents a formalisation for the resource-aware placement of security VNFs and provides a constraint programming solution along with examining heuristic, meta-heuristic and near-optimal/subset-sum solutions to solve larger size problems in reduced time. The results of this work identify the unique and vital constraints of the placement of security functions. They demonstrate that the granularity of the traffic required by the security functions imposes traffic constraints that increase the resource overhead of the deployment. The work identifies the north-south traffic in data centers as the traffic designed for processing for security functions rather than east-west traffic. It asserts that the non-sharing strategy of security modules will reduce the complexity in case of the multi-tenant environment. Furthermore, the work adopts on-path deployment of security VNF traffic strategy, which is shown to reduce resources overhead compared to previous approaches

    Cyber-Physical Security of Wide-Area Frequency-based Applications in Power Systems

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    Modern power systems are continuously developing into large and interconnected ones. However, at the same time, restructuring within the power industry and reduced investment in transmission system expansions mean that power systems are operating closer and closer to their limits, leaving them more vulnerable to fault outages than before. The aspects of protection and control within power systems have thus become increasingly important as well as complicated. Concurrently, the continuous technological development in communication and measurement has accelerated the occurrence and application of Wide-Area Monitoring, Protection and Control (WAMPAC), a new kind of advanced scheme based on wide-area measurements. The blackouts happening in North America as well as in other countries over the past few years are also providing more incentives to scientists and engineers to study wide-area protection and control systems. Communication networks in smart grids bring increased connectivity at the cost of increased security vulnerabilities and challenges. A smart grid can be a prime target for cyber terrorism because of its critical nature. As a result, smart grid security has already attracted significant attention from governments, the energy industry, and consumers, leading to several important studies. WAMPAC is the concept of using system-wide information via a centralized control center or Energy Management System (EMS) to monitor and control the whole system. Based on the situation and the required control action, the control center shares selected data with specific remote locations that are in need of the data. The utilization of system-wide information makes it easier to monitor the entire system and make better control and protection decisions by the EMS. Although the communication system is the backbone of these recent schemes, it makes them vulnerable to different types of cyber attacks. This thesis aims to investigate the problem of cyber security in frequency-related WAMPAC schemes. Two main schemes are considered as case studies: Automatic Generation Control(AGC) and Wide-Area Under-Frequency Load Shedding (WAUFLS) protection schemes. In addition, the cyber security of Power System State Estimation (PSSE), as a Wide-Area Monitoring (WAM) scheme, has been revisited. As WAMPAC schemes are so varied in their purpose and implementation, there is no general analysis to illustrate the potential impact of a cyber attack on all such schemes. However, some general types of system responses are considered in this work. First, with regard to AGC systems, a Kalman filter-based approach is proposed to detect False Data Injection (FDI) in AGC systems. Because detecting FDI and removing the compromised measurements are not enough in practical situations, the use of a simultaneous input and state estimation-based algorithm to detect and concurrently compensate for FDI attacks against the measurements of AGC systems is investigated. Throughout the use of this algorithm, the FDI attack signal is dealt with as an unknown input and its value is estimated accordingly. Then, the estimated value for the FDI is used to compensate for the effect of the attack so that the control center makes its decisions based on the corrected sensor signals, not the manipulated ones. Unlike other approaches, and as an extension to this work, the effect of AGC nonlinearities is studied during the attack time. Recurrent Neural Networks (RNN)-based approach is proposed to detect FDI during a time where any of the nonlinearities is affecting the system. The RNN-based approach is used to classify and identify the attacks according to their behavior. Second, with regard to WAUFLS protection schemes, this thesis investigates the problem of cyber attacks on WAUFLS. This is followed by a detailed analysis showing that an adversary can launch an FDI attack against existing WAUFLS schemes in three different ways depending on they access level to system data, which may lead to equipment damage and/or system-wide blackout. To address this issue, a new mitigation scheme, that is ro-bust against cyber attacks, is proposed to mitigate the effect of FDI attacks on WAUFLS. The proposed scheme depends on trusted system states to run power flow, so the power mismatch in the system is calculated. Finally, the calculated magnitude of disturbance is used to decide on the amount and locations of the load shedding. All proposed detection and mitigation methods in the thesis are tested using simulations of practical systems. In addition, sensitivity analysis is given after each method

    Security Technologies and Methods for Advanced Cyber Threat Intelligence, Detection and Mitigation

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    The rapid growth of the Internet interconnectivity and complexity of communication systems has led us to a significant growth of cyberattacks globally often with severe and disastrous consequences. The swift development of more innovative and effective (cyber)security solutions and approaches are vital which can detect, mitigate and prevent from these serious consequences. Cybersecurity is gaining momentum and is scaling up in very many areas. This book builds on the experience of the Cyber-Trust EU project’s methods, use cases, technology development, testing and validation and extends into a broader science, lead IT industry market and applied research with practical cases. It offers new perspectives on advanced (cyber) security innovation (eco) systems covering key different perspectives. The book provides insights on new security technologies and methods for advanced cyber threat intelligence, detection and mitigation. We cover topics such as cyber-security and AI, cyber-threat intelligence, digital forensics, moving target defense, intrusion detection systems, post-quantum security, privacy and data protection, security visualization, smart contracts security, software security, blockchain, security architectures, system and data integrity, trust management systems, distributed systems security, dynamic risk management, privacy and ethics

    Security Technologies and Methods for Advanced Cyber Threat Intelligence, Detection and Mitigation

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    The rapid growth of the Internet interconnectivity and complexity of communication systems has led us to a significant growth of cyberattacks globally often with severe and disastrous consequences. The swift development of more innovative and effective (cyber)security solutions and approaches are vital which can detect, mitigate and prevent from these serious consequences. Cybersecurity is gaining momentum and is scaling up in very many areas. This book builds on the experience of the Cyber-Trust EU project’s methods, use cases, technology development, testing and validation and extends into a broader science, lead IT industry market and applied research with practical cases. It offers new perspectives on advanced (cyber) security innovation (eco) systems covering key different perspectives. The book provides insights on new security technologies and methods for advanced cyber threat intelligence, detection and mitigation. We cover topics such as cyber-security and AI, cyber-threat intelligence, digital forensics, moving target defense, intrusion detection systems, post-quantum security, privacy and data protection, security visualization, smart contracts security, software security, blockchain, security architectures, system and data integrity, trust management systems, distributed systems security, dynamic risk management, privacy and ethics

    Deep Learning -Powered Computational Intelligence for Cyber-Attacks Detection and Mitigation in 5G-Enabled Electric Vehicle Charging Station

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    An electric vehicle charging station (EVCS) infrastructure is the backbone of transportation electrification. However, the EVCS has various cyber-attack vulnerabilities in software, hardware, supply chain, and incumbent legacy technologies such as network, communication, and control. Therefore, proactively monitoring, detecting, and defending against these attacks is very important. The state-of-the-art approaches are not agile and intelligent enough to detect, mitigate, and defend against various cyber-physical attacks in the EVCS system. To overcome these limitations, this dissertation primarily designs, develops, implements, and tests the data-driven deep learning-powered computational intelligence to detect and mitigate cyber-physical attacks at the network and physical layers of 5G-enabled EVCS infrastructure. Also, the 5G slicing application to ensure the security and service level agreement (SLA) in the EVCS ecosystem has been studied. Various cyber-attacks such as distributed denial of services (DDoS), False data injection (FDI), advanced persistent threats (APT), and ransomware attacks on the network in a standalone 5G-enabled EVCS environment have been considered. Mathematical models for the mentioned cyber-attacks have been developed. The impact of cyber-attacks on the EVCS operation has been analyzed. Various deep learning-powered intrusion detection systems have been proposed to detect attacks using local electrical and network fingerprints. Furthermore, a novel detection framework has been designed and developed to deal with ransomware threats in high-speed, high-dimensional, multimodal data and assets from eccentric stakeholders of the connected automated vehicle (CAV) ecosystem. To mitigate the adverse effects of cyber-attacks on EVCS controllers, novel data-driven digital clones based on Twin Delayed Deep Deterministic Policy Gradient (TD3) Deep Reinforcement Learning (DRL) has been developed. Also, various Bruteforce, Controller clones-based methods have been devised and tested to aid the defense and mitigation of the impact of the attacks of the EVCS operation. The performance of the proposed mitigation method has been compared with that of a benchmark Deep Deterministic Policy Gradient (DDPG)-based digital clones approach. Simulation results obtained from the Python, Matlab/Simulink, and NetSim software demonstrate that the cyber-attacks are disruptive and detrimental to the operation of EVCS. The proposed detection and mitigation methods are effective and perform better than the conventional and benchmark techniques for the 5G-enabled EVCS

    Vulnerability Assessment and Privacy-preserving Computations in Smart Grid

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    Modern advances in sensor, computing, and communication technologies enable various smart grid applications which highlight the vulnerability that requires novel approaches to the field of cybersecurity. While substantial numbers of technologies have been adopted to protect cyber attacks in smart grid, there lacks a comprehensive review of the implementations, impacts, and solutions of cyber attacks specific to the smart grid.In this dissertation, we are motivated to evaluate the security requirements for the smart grid which include three main properties: confidentiality, integrity, and availability. First, we review the cyber-physical security of the synchrophasor network, which highlights all three aspects of security issues. Taking the synchrophasor network as an example, we give an overview of how to attack a smart grid network. We test three types of attacks and show the impact of each attack consisting of denial-of-service attack, sniffing attack, and false data injection attack.Next, we discuss how to protect against each attack. For protecting availability, we examine possible defense strategies for the associated vulnerabilities.For protecting data integrity, a small-scale prototype of secure synchrophasor network is presented with different cryptosystems. Besides, a deep learning based time-series anomaly detector is proposed to detect injected measurement. Our approach observes both data measurements and network traffic features to jointly learn system states and can detect attacks when state vector estimator fails.For protecting data confidentiality, we propose privacy-preserving algorithms for two important smart grid applications. 1) A distributed privacy-preserving quadratic optimization algorithm to solve Security Constrained Optimal Power Flow (SCOPF) problem. The SCOPF problem is decomposed into small subproblems using the Alternating Direction Method of Multipliers (ADMM) and gradient projection algorithms. 2) We use Paillier cryptosystem to secure the computation of the power system dynamic simulation. The IEEE 3-Machine 9-Bus System is used to implement and demonstrate the proposed scheme. The security and performance analysis of our implementations demonstrate that our algorithms can prevent chosen-ciphertext attacks at a reasonable cost

    Network Intrusion Detection System using Deep Learning Technique

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    The rise in the usage of the internet in this recent time had led to tremendous development in computer networks with large volumes of information transported daily. This development has generated lots of security threats and privacy concerns on networks and data. To tackle these issues, several protective measures have been developed including the Intrusion Detection Systems (IDSs). IDS plays a major backbone in network security and provides an extra layer of security to other security defence mechanisms in a network. However, existing IDS built on a signature base such as snort and the likes are unable to detect unknown and novel threats. Anomaly detection-based IDSs that use Machine Learning (ML) approaches are not scalable when enormous data are presented, and during modelling, the runtime increases as the dataset size increases which needs high computational resources to fulfil the runtime requirements. This thesis proposes a Feedforward Deep Neural Network (FFDNN) for an intrusion detection system that performs a binary classification on the popular NSL-Knowledge discovery and data mining (NSL-KDD) dataset. The model was developed from Keras API integrated into TensorFlow in Google's colaboratory software environment. Three variants of FFDNNs were trained using the NSL-KDD dataset and the network architecture consisted of two hidden layers with 64 and 32; 32 and 16; 512 and 256 neurons respectively, and each with the ReLu activation function. The sigmoid activation function for binary classification was used in the output layer and the prediction loss function used was the binary cross-entropy. Regularization was set to a dropout rate of 0.2 and the Adam optimizer was used. The deep neural networks were trained for 16, 20, 20 epochs respectively for batch sizes of 256, 64, and 128. After evaluating the performances of the FFDNNs on the training data, the prediction was made on test data, and accuracies of 89%, 84%, and 87% were achieved. The experiment was also conducted on the same training dataset (NSL-KDD) using the conventional machine learning algorithms (Random Forest; K-nearest neighbor; Logistic regression; Decision tree; and Naïve Bayes) and predictions of each algorithm on the test data gave different performance accuracies of 81%, 76%, 77%, 77%, 77%, respectively. The performance results of the FFDNNs were calculated based on some important metrics (FPR, FAR, F1 Measure, Precision), and these were compared to the conventional ML algorithms and the outcome shows that the deep neural networks performed best due to their dense architecture that made it scalable with the large size of the dataset and also offered a faster run time during training in contrast to the slow run time of the Conventional ML. This implies that when the dataset is large and a faster computation is required, then FFDNN is a better choice for best performance accuracy
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