Moving Target Defense Strategies Research Articles

MTD-Diorama: Moving Target Defense Visualization Engine for Systematic Cybersecurity Strategy Orchestration.

With the advancement in information and communication technology, modern society has relied on various computing systems in areas closely related to human life. However, cyberattacks are also becoming more diverse and intelligent, with personal information and human lives being threatened. The moving target defense (MTD) strategy was designed to protect mission-critical systems from cyberattacks. The MTD strategy shifted the paradigm from passive to active system defense. However, there is a lack of indicators that can be used as a reference when deriving general system components, making it difficult to configure a systematic MTD strategy. Additionally, even when selecting system components, a method to confirm whether the systematic components are selected to respond to actual cyberattacks is needed. Therefore, in this study, we surveyed and analyzed existing cyberattack information and MTD strategy research results to configure a component dataset. Next, we found the correlation between the cyberattack information and MTD strategy component datasets and used this to design and implement the MTD-Diorama data visualization engine to configure a systematic MTD strategy. Through this, researchers can conveniently identify the attack surface contained in cyberattack information and the MTD strategies that can respond to each attack surface. Furthermore, it will allow researchers to configure more systematic MTD strategies that can be used universally without being limited to specific computing systems.

MMTD: Multistage Moving Target Defense for Security-Enhanced D-FACTS Operation

In recent studies, moving target defense (MTD) has been applied to detect false data injection (FDI) attacks using distributed flexible AC transmission system (D-FACTS) devices. However, the inherent conflict between the security goals of MTD (i.e., detecting FDI attacks) and the economic goals of D-FACTS devices (i.e., reducing power losses) would impede the application of MTD in real systems. Moreover, the detection capabilities of existing MTDs are often insufficient. This paper proposes a multi-stage MTD (MMTD) approach to resolve these two issues by adding a group of designed security-oriented schemes before D-FACTS’ economy-oriented scheme to detect FDI attacks. We keep these security-oriented schemes for a very short time interval and then revert to the economy-oriented scheme for the remaining time to ensure the economic requirements. We prove that a designed MMTD can significantly improve the detection capability compared to existing one-stage MTDs. We find the supremum of MMTD’s detection capability and study its relationship with system topology and D-FACTS deployment. Meanwhile, a greedy algorithm is proposed to search the MMTD strategy to reach this supremum. Simulation results show that the proposed MMTD can achieve the supremum against FDI attacks while outperforming current MTD strategies on economic indicators.

A Comprehensive Architectural Framework of Moving Target Defenses Against DDoS Attacks

Distributed Denial-of-Service (DDoS) attacks are among the top toughest security threats in today’s cyberspace. The multitude, diversity, and variety of both the attacks and their countermeasures have the consequence that no optimal solutions exist. However, many mitigation techniques and strategies have been proposed among which is Moving Target Defense (MTD). MTD strategy keeps changing the system states and attack surface dynamically by continually applying various systems reconfigurations aiming at increasing the uncertainty and complexity for attackers. Current proposals of MTD fall into one of three strategies: shuffling, diversity, and redundancy, based on what to move? how to move? and when to move? Despite the existence of such strategies, a comprehensive Framework for MTD techniques against DDoS attacks that can be used for all types of DDoS attacks has not been proposed yet. In this paper, we propose a novel and comprehensive Framework of MTD techniques considering all stages, mechanisms, data sources, and criteria adopted by the research community, the Framework will apply to all DDoS attacks on different systems. To efficiently use our proposed model, a comprehensive taxonomy of MTD mitigation techniques and strategies is also provided and can be used as a reference guide for the best selection of the model’s parameters.

A Brief Survey of Recent Advances and Methodologies for the Security Control of Complex Cyber-Physical Networks.

Complex cyber-physical networks combine the prominent features of complex networks and cyber-physical systems (CPSs), and the interconnections between the cyber layer and physical layer usually pose significant impacts on its normal operation. Many vital infrastructures, such as electrical power grids, can be effectively modeled as complex cyber-physical networks. Given the growing importance of complex cyber-physical networks, the issue of their cybersecurity has become a significant concern in both industry and academic fields. This survey is focused on some recent developments and methodologies for secure control of complex cyber-physical networks. Besides the single type of cyberattack, hybrid cyberattacks are also surveyed. The examination encompasses both cyber-only hybrid attacks and coordinated cyber-physical attacks that leverage the strengths of both physical and cyber attacks. Then, special focus will be paid to proactive secure control. Reviewing existing defense strategies from topology and control perspectives aims to proactively enhance security. The topological design allows the defender to resist potential attacks in advance, while the reconstruction process can aid in reasonable and practical recovery from unavoidable attacks. In addition, the defense can adopt active switching-based control and moving target defense strategies to reduce stealthiness, increase the cost of attacks, and limit the attack impacts. Finally, conclusions are drawn and some potential research topics are suggested.

Explicit Analysis on Effectiveness and Hiddenness of Moving Target Defense in AC Power Systems

Moving target defense (MTD) is becoming promising in thwarting the false data injection attacks (FDIAs) on power system state estimation (SE). However, due to the nonlinear dynamics of AC power systems, the investigation of the general evaluation metrics of MTD, namely the effectiveness in terms of attack detection and the hiddenness, is still challenging. To this end, in this paper, we attempt to conduct an explicit analysis on the MTD performance in AC power systems. First, we derive explicit approximations of measurement residuals to quantify the two metrics. Then, based on the projection matrix, maximizing the effectiveness is transformed to maximizing the lower bound of the approximated residual, under which the matrix inverse issue is addressed. Moreover, the maximization of hiddenness is achieved by the minimization of the approximated power flow difference caused by reactance perturbation. To balance the trade-off between effectiveness and hiddenness, the design of explicit residual-based MTD (EXR-MTD) is accomplished by aggregating the two sub-problems with an appropriate weight. Finally, extensive simulations are conducted to validate the performance of EXR-MTD. Numerical results indicate that EXR-MTD performs better than existing MTD strategies in terms of hiddenness, while the effectiveness of EXR-MTD is comparable to those of existing MTD strategies.

IoDM: A Study on a IoT-Based Organizational Deception Modeling with Adaptive General-Sum Game Competition

Moving target defense (MTD) and decoy strategies, measures of active defense, were introduced to secure both the proactive security and reactive adaptability of internet-of-things (IoT) networks that have been explosively applied to various industries without any strong security measures and to mitigate the side effects of threats. However, the existing MTD and decoy strategies are limited to avoiding the attacker’s reconnaissance and initial intrusion attempts through simple structural mutations or inducing the attackers to a static trap based on the deceptive path and lack approaches to adaptively optimize IoT in consideration of the unique characteristic information by the domain of IoT. Game theory-based and decoy strategies are other options; however, they do not consider the dynamicity and uncertainty of the decision-making stages by the organizational agent related to the IoT domains. Therefore, in this paper, we present a type of organizational deception modeling, namely IoT-based organizational deception modeling (IoDM), which considers both the dynamic topologies and organizational business fingerprints customized in the IoT domain and operational purpose. For this model, we considered the practical scalability of the existing IoT-enabled MTD and decoy concepts and formulated the partially incomplete deceptive decision-making modeling for the cyber-attack and defense competition for IoT in real-time based on the general-sum game. According to our experimental results, the efficiency of the deceptive defense of the IoT defender could be improved by 70% on average while deriving the optimal defense cost compared to the increased defense performance. The findings of this study will improve the deception performances of MTD and decoy strategies by IoT scenarios related to various operational domains such as smart home networks, industrial networks, and medical networks. To the best of our knowledge, this study has employed social-engineering IoT knowledge and general-sum game theory for the first time.

Finding Optimal Moving Target Defense Strategies: A Resilience Booster for Connected Cars

During their life-cycle, modern connected cars will have to face various and changing security threats. As for any critical embedded system, security fixes in the form of software updates need to be thoroughly verified and cannot be deployed on a daily basis. The system needs to commit to a defense strategy, while attackers can examine vulnerabilities and prepare possible exploits before attacking. In order to break this asymmetry, it can be advantageous to use proactive defenses, such as reconfiguring parts of the system configuration. However, resource constraints and losses in quality of service need to be taken into account for such Moving Target Defenses (MTDs). In this article, we present a game-theoretic model that can be used to compute an optimal MTD defense for a critical embedded system that is facing several attackers with different objectives. The game is resolved using off-the-shelf MILP solvers. We validated the method with an automotive use case and conducted extensive experiments to evaluate its scalability and stability.

Performance assessment of hybrid MTD for DoS mitigation in public cloud

The massive features of cloud computing makes it as an attractive target in today's business community. Public cloud draws immediate attention among individuals, organizations due to its pay-as-you-go model. Security, reliability, and regulatory compliance are the principal key concerns in the public cloud environment as its success relies merely on addressing those concerns. Denial of Service (DoS) attack is one of the major attack categories in the cloud. Despite the emergence of automated and advanced attack control measures in place, the blooming and morphing nature of DoS attacks are truly devastative in disrupting the service availability. Moving Target Defense (MTD) is an emerging technique to achieve the diversity criterion for improving the network resiliency against DoS. The prominent solution against DoS mitigation could be achieved using a combination of MTD strategies for increased uncertainty. Hence, the proposed technique combines the shuffle, diversity, and redundancy strategies of MTD which yields increased uncertainty, reduced attack probability values, and early attack detection with Access Control List (ACL) rules. 0.1% is the attack probability value achieved based on experimental simulations in the Amazon Web Service (AWS) environment.

Physical resilience to insider attacks in IoT networks: Independent cryptographically secure sequences for DSSS anti-jamming

Wireless communication is a key technology for the Internet of Things (IoT). Due to its open nature, the physical layer of wireless systems is a high-priority target for an adversary whose goal is to disrupt the normal behavior of the system. In particular, jamming attacks are one of the most straightforward and effective types of attacks: information flow of the system is stopped or severely disturbed. In this paper, we propose a method to improve the jamming resilience of IoT systems based on Direct-Sequence Spread-Spectrum (DSSS) techniques. Our proposal is inspired by the Moving Target Defense (MTD) paradigm. MTD strategies randomize components of a system, increasing the effort an attacker needs to compromise the system. We use state-of-the-art Cryptographically Secure Pseudo-Random Number Generators outputs as spreading sequences for DSSS. The sequences of the proposed system are generated in an ad-hoc, independent, and distributed way. We show probabilistically that the generated sequences have robust cross-correlation properties. We define a multi-user system model to evaluate the Bit-Error-Rate of our proposal in the presence of two types of jammers: a classical band-limited Gaussian noise jammer, and an insider smart jammer with knowledge of one spreading sequence used in the system. Our proposal proactively mitigates the insider jammer attack. We quantify the insider smart jammer resilience of a system implementing our proposal, as a function of the length of the spreading sequences and the jammer power.

A Survey on the Moving Target Defense Strategies: An Architectural Perspective

As the complexity and the scale of networks continue to grow, the management of the network operations and security defense has become a challenging task for network administrators, and many network devices may not be updated timely, leaving the network vulnerable to potential attacks. Moreover, the static nature of our existing network infrastructure allows attackers to have enough time to study the static configurations of the network and to launch well-crafted attacks at their convenience while defenders have to work around the clock to defend the network. This asymmetry, in terms of time and money invested, has given attackers greater advantage than defenders and has made the security defense even more challenging. It calls for new and innovative ideas to fix the problem. Moving Target Defense (MTD) is one of the innovative ideas which implements diverse and dynamic configurations of network systems with the goal of puzzling the exact attack surfaces available to attackers. As a result, the system status with the MTD strategy is unpredictable to attackers, hard to exploit, and is more resilient to various forms of attacks. There are existing survey papers on various MTD techniques, but to the best of our knowledge, insufficient focus was given on the architectural perspective of MTD strategies or some new technologies such as Internet of Things (IoT). This paper presents a comprehensive survey on MTD and implementation strategies from the perspective of the architecture of the complete network system, covering the motivation for MTD, the explanation of main MTD concepts, ongoing research efforts of MTD and its implementation at each level of the network system, and the future research opportunities offered by new technologies such as Software-Defined Networking (SDN) and Internet of Things (IoT).

CAN ID Shuffling Technique (CIST): Moving Target Defense Strategy for Protecting In-Vehicle CAN

New vehicles have become increasingly targeted for cyber-attacks as their rate of digitalization is accelerated. Research on vehicle hacking has highlighted the security vulnerabilities of in-vehicle controller area networks (CANs) as the biggest problem. In particular, a CAN does not offer access control, authentication, or confidentiality, so it fails to prevent reconnaissance operations conducted by an adversary. Because its static configuration (CAN ID, data frame transmission cycle, and data field format) is used in an in-vehicle network environment, the adversary can conduct reconnaissance and easily acquire information to be used for an attack. One of the moving target defense strategies, network address shuffling (NAS), is an extremely practical security solution that can prevent in-vehicle CAN reconnaissance acts. In this paper, we propose a CAN ID shuffling technique using NAS. Our proposed security solution aims to increase the cost burden for the adversary to analyze CAN data frames. To evaluate the performance of the proposed security solution, we conducted an evaluation based on a labcar. Our proposed security solution may be implemented without altering the unique characteristics of the CAN standard. Hence, it can be used as a practical countermeasure to solve the problems affecting in-vehicle CANs.

DSEOM: A Framework for Dynamic Security Evaluation and Optimization of MTD in Container-based Cloud

Due to the lightweight features, the combination of container technology and microservice architecture makes container-based cloud environment more efficient and agile than VM-based cloud environment. However, it also greatly amplifies the dynamism and complexity of the cloud environment and increases the uncertainty of security issues in the system concurrently. In this case, the effectiveness of defense mechanisms with fixed strategies would fluctuate as the updates occur in cloud environment. We refer this problem as effectiveness drift problem of defense mechanisms, which is particularly acute in the proactive defense mechanisms, such as moving target defense (MTD). To tackle this problem, we present DSEOM, a framework that can automatically perceive updates of container-based cloud environment, rapidly evaluate the effectiveness change of MTD and dynamically optimize MTD strategies. Specifically, we establish a multi-dimensional attack graphs model to formalize various complex attack scenarios. Combining with this model, we introduce the concept of betweenness centrality to effectively evaluate and optimize the implementation strategies of MTD. In addition, we present a series of security and performance metrics to quantify the effectiveness of MTD strategies in DSEOM. And we conduct extensive experiments to illustrate the existence of the effectiveness drift problem and demonstrate the usability and scalability of DSEOM.

Path Hopping: An MTD Strategy for Long-Term Quantum-Safe Communication

Moving target defense (MTD) strategies have been widely studied for securing computer systems. We consider using MTD strategies to provide long-term cryptographic security for message transmission against an eavesdropping adversary who has access to a quantum computer. In such a setting, today’s widely used cryptographic systems including Diffie-Hellman key agreement protocol and RSA cryptosystem will be insecure and alternative solutions are needed. We will use a physical assumption, existence of multiple communication paths between the sender and the receiver, as the basis of security, and propose a cryptographic system that uses this assumption and an MTD strategy to guarantee efficient long-term information theoretic security even when only a single path is not eavesdropped. Following the approach of Maleki et al., we model the system using a Markov chain, derive its transition probabilities, propose two security measures, and prove results that show how to calculate these measures using transition probabilities. We define two types of attackers that we call risk-taking and risk-averse and compute our proposed measures for the two types of adversaries for a concrete MTD strategy. We will use numerical analysis to study tradeoffs between system parameters, discuss our results, and propose directions for future research.

Moving target defense: state of the art and characteristics

Moving target defense (MTD) has emerged as one of the game-changing themes to alter the asymmetric situation between attacks and defenses in cyber-security. Numerous related works involving several facets of MTD have been published. However, comprehensive analyses and research on MTD are still absent. In this paper, we present a survey on MTD technologies to scientifically and systematically introduce, categorize, and summarize the existing research works in this field. First, a new security model is introduced to describe the changes in the traditional defense paradigm and security model caused by the introduction of MTD. A function-and-movement model is provided to give a panoramic overview on different perspectives for understanding the existing MTD research works. Then a systematic interpretation of published literature is presented to describe the state of the art of the three main areas in the MTD field, namely, MTD theory, MTD strategy, and MTD evaluation. Specifically, in the area of MTD strategy, the common characteristics shared by the MTD strategies to improve system security and effectiveness are identified and extrapolated. Thereafter, the methods to implement these characteristics are concluded. Moreover, the MTD strategies are classified into three types according to their specific goals, and the necessary and sufficient conditions of each type to create effective MTD strategies are then summarized, which are typically one or more of the aforementioned characteristics. Finally, we provide a number of observations for the future direction in this field, which can be helpful for subsequent researchers.