Biblio

At present, the network architecture is based on the TCP/IP protocol and node communications are achieved by the IP address and identifier of the node. The IP address in the network remains basically unchanged, so it is more likely to be attacked by network intruder. To this end, it is important to make periodic dynamic hopping in a specific address space possible, so that an intruder fails to obtain the internal network address and grid topological structure in real time and to continue to perform infiltration by the building of a new address space layout randomization system on the basis of SDN from the perspective of an attacker.

Large scale cloud networks consist of distributed networking and computing elements that process critical information and thus security is a key requirement for any environment. Unfortunately, assessing the security state of such networks is a challenging task and the tools used in the past by security experts such as packet filtering, firewall, Intrusion Detection Systems (IDS) etc., provide a reactive security mechanism. In this paper, we introduce a Moving Target Defense (MTD) based proactive security framework for monitoring attacks which lets us identify and reason about multi-stage attacks that target software vulnerabilities present in a cloud network. We formulate the multi-stage attack scenario as a two-player zero-sum Markov Game (between the attacker and the network administrator) on attack graphs. The rewards and transition probabilities are obtained by leveraging the expert knowledge present in the Common Vulnerability Scoring System (CVSS). Our framework identifies an attacker's optimal policy and places countermeasures to ensure that this attack policy is always detected, thus forcing the attacker to use a sub-optimal policy with higher cost.

Information security is a top priority in government and industry because high consequence cyber incidents continue with regularity. The blue teamers that protect cyber systems cannot stop or even know about all these incidents, so they must take measures to tolerate these incursions in addition to preventing and detecting them. We propose dynamically compartmentalizing subject networks into collaboration zones and limiting the communication between these zones. In this article, we demonstrate this technique's effect on the attacker and the defender for various parameter settings using discrete-time simulation. Based on our results, we conclude that dynamic cyber zone defense is a viable intrusion tolerance technique and should be considered for technology transfer.

Moving target defense (MTD) is becoming popular with the advancements in Software Defined Networking (SDN) technologies. With centralized management through SDN, changing the network attributes such as routes to escape from attacks is simple and fast. Yet, the available alternate routes are bounded by the network topology, and a persistent attacker that continuously perform the reconnaissance can extract the whole link-map of the network. To address this issue, we propose to use virtual shadow networks (VSNs) by applying Network Function Virtualization (NFV) abilities to the network in order to deceive attacker with the fake topology information and not reveal the actual network topology and characteristics. We design this approach under a formal framework for Internet Service Provider (ISP) networks and apply it to the recently emerged indirect DDoS attacks, namely Crossfire, for evaluation. The results show that attacker spends more time to figure out the network behavior while the costs on the defender and network operations are negligible until reaching a certain network size.

In this paper, a dynamic cybersecurity protection method based on software-defined networking (SDN) is proposed, according to the protection requirement analysis for industrial control systems (ICSs). This method can execute security response measures by SDN, such as isolation, redirection etc., based on the real-time intrusion detection results, forming a detecting-responding closed-loop security control. In addition, moving target defense (MTD) concept is introduced to the protection for ICSs, where topology transformation and IP/port hopping are realized by SDN, which can confuse and deceive the attackers and prevent attacks at the beginning, protection ICSs in an active manner. The simulation results verify the feasibility of the proposed method.

The safety of web browsers is essential to the privacy of Internet users and the security of their computing systems. In the last few years, there have been several cyber attacks geared towards compromising surfers' data and systems via exploiting browser-based vulnerabilities. Android and a number of mobile operating systems have been supporting a UI component called WebView, which can be embedded in any mobile application to render the web contents. Yet, this mini-browser component has been found to be vulnerable to various kinds of attacks. For instance, an attacker in her WebView-Embedded app can inject malicious JavaScripts into the WebView to modify the web contents or to steal user's input values. This kind of attack is particularly challenging due to the full control of attackers over the content of the loaded pages. In this paper, we are proposing and testing a server-side moving target defense technique to counter the risk of JavaScript injection attacks on mobile WebViews. The solution entails creating redundant HTML forms, randomizing their attributes and values, and asserting stealthy prompts for the user data. The solution does not dictate any changes to the browser or applications codes, neither it requires key sharing with benign clients. The results of our performance and security analysis suggest that our proposed approach protects the confidentiality and integrity of user input values with minimum overhead.

In this paper, we consider the problem of designing system parameters to improve detection of attacks in control systems. Specifically, we study control systems which are vulnerable to integrity attacks on sensors and actuators. We aim to defend against strong model aware adversaries that can read and modify all sensors and actuators. Previous work has proposed a moving target defense for detecting integrity attacks on control systems. Here, an authenticating subsystem with time-varying dynamics coupled to the original plant is introduced. Due to this coupling, an attack on the original system will affect the authenticating subsystem and in turn be revealed by a set of sensors measuring the extended plant. Moreover, the time-varying dynamics of the extended plant act as a moving target, preventing an adversary from developing an effective adaptive attack strategy. Previous work has failed to consider the design of the time-varying system matrices and as such provides little in terms of guidelines for implementation in real systems. This paper proposes two optimization problems for designing these matrices. The first designs the auxiliary actuators to maximize detection performance while the second designs the coupling matrices to maximize system estimation performance. Numerical examples are presented that validate our approach.

Big data platforms have grown popular for real-time stream processing on distributed clusters and clouds. However, execution of sensitive streaming applications on shared computing resources increases their vulnerabilities, and may lead to data leaks and injection of spurious logic that can compromise these applications. Here, we adopt Moving Target Defense (MTD) techniques into Fast Data platforms, and propose MTD strategies by which we can mitigate these attacks. Our strategies target the platform, application and data layers, which make these reusable, rather than the OS, virtual machine, or hardware layers, which are environment specific. We use Apache Storm as the canonical distributed stream processing platform for designing our MTD strategies, and offer a preliminary evaluation that indicates the feasibility and evaluates the performance overheads.

Software-defined networking (SDN) allows the smart grid to be centrally controlled and managed by decoupling the control plane from the data plane, but it also expands attack surface for attackers. Existing studies about the security of SDN-enabled smart grid (SDSG) mainly focused on static methods such as access control and identity authentication, which is vulnerable to attackers that carefully probe the system. As the attacks become more variable and complex, there is an urgent need for dynamic defense methods. In this paper, we propose a security function virtualization (SFV) based moving target defense of SDSG which makes the attack surface constantly changing. First, we design a dynamic defense mechanism by migrating virtual security function (VSF) instances as the traffic state changes. The centralized SDN controller is re-designed for global status monitoring and migration management. Moreover, we formalize the VSF instances migration problem as an integer nonlinear programming problem with multiple constraints and design a pre-migration algorithm to prevent VSF instances' resources from being exhausted. Simulation results indicate the feasibility of the proposed scheme.

This paper introduces an approach based on control theory to model, analyze and select optimal security policies for Moving Target Defense (MTD) deployment strategies. A Markov Decision Process (MDP) scheme is presented to model states of the system from attacking point of view. The employed value iteration method is based on the Bellman optimality equation for optimal policy selection for each state defined in the system. The model is then utilized to analyze the impact of various costs on the optimal policy. The MDP model is then applied to two case studies to evaluate the performance of the model.

Distributed Denial of Service attack is very harmful to software-defined networking. Effective defense measures are the key to ensure SDN security. An adaptive moving target defense scheme based on end information hopping for SDN is proposed. The source address entropy value and the flow rate method are used to detect the network condition. According to the detection result, the end information is adjusted by time adaptive or space adaptive. A model of active network defense is constructed. The experimental results show that the proposed scheme enhances the anti-attack capability and serviceability compared with other methods, and has greater dynamics and flexibility.

With the interconnection of services and customers, network attacks are capable of large amounts of damage. Flexible Random Virtual IP Multiplexing (FRVM) is a Moving Target Defence (MTD) technique that protects against reconnaissance and access with address mutation and multiplexing. Security techniques must be trusted, however, FRVM, along with past MTD techniques, have gaps in realistic evaluation and thorough analysis of security and performance. FRVM, and two comparison techniques, were deployed on a virtualised network to demonstrate FRVM's security and performance trade-offs. The key results include the security and performance trade-offs of address multiplexing and address mutation. The security benefit of IP address multiplexing is much greater than its performance overhead, deployed on top of address mutation. Frequent address mutation significantly increases an attackers' network scan durations as well as effectively obfuscating and hiding network configurations.

The root cause of cross-site scripting(XSS) attack is that the JavaScript engine can't distinguish between the JavaScript code in Web application and the JavaScript code injected by attackers. Moving Target Defense (MTD) is a novel technique that aim to defeat attacks by frequently changing the system configuration so that attackers can't catch the status of the system. This paper describes the design and implement of a XSS defense method based on Moving Target Defense technology. This method adds a random attribute to each unsafe element in Web application to distinguish between the JavaScript code in Web application and the JavaScript code injected by attackers and uses a security check function to verify the random attribute, if there is no random attribute or the random attribute value is not correct in a HTML (Hypertext Markup Language) element, the execution of JavaScript code will be prevented. The experiment results show that the method can effectively prevent XSS attacks and have little impact on the system performance.

Microservice Architectures (MSA) structure applications as a collection of loosely coupled services that implement business capabilities. The key advantages of MSA include inherent support for continuous deployment of large complex applications, agility and enhanced productivity. However, studies indicate that most MSA are homogeneous, and introduce shared vulnerabilites, thus vulnerable to multi-step attacks, which are economics-of-scale incentives to attackers. In this paper, we address the issue of shared vulnerabilities in microservices with a novel solution based on the concept of Moving Target Defenses (MTD). Our mechanism works by performing risk analysis against microservices to detect and prioritize vulnerabilities. Thereafter, security risk-oriented software diversification is employed, guided by a defined diversification index. The diversification is performed at runtime, leveraging both model and template based automatic code generation techniques to automatically transform programming languages and container images of the microservices. Consequently, the microservices attack surfaces are altered thereby introducing uncertainty for attackers while reducing the attackability of the microservices. Our experiments demonstrate the efficiency of our solution, with an average success rate of over 70% attack surface randomization.

We consider a moving-target defense of a proxied multiserver tenant of the cloud where the proxies dynamically change to defeat reconnaissance activity by a botnet planning a DDoS attack targeting the tenant. Unlike the system of [4] where all proxies change simultaneously at a fixed rate, we consider a more “responsive” system where the proxies may change more rapidly and selectively based on the current session request intensity, which is expected to be abnormally large during active reconnaissance. In this paper, we study a tractable “adversarial” coupon-collector model wherein proxies change after a random period of time from the latest request, i.e., asynchronously. In addition to determining the stationary mean number of proxies discovered by the attacker, we study the age of a proxy (coupon type) when it has been identified (requested) by the botnet. This gives us the rate at which proxies change (cost to the defender) when the nominal client request load is relatively negligible.

Conventional SDN-based MTD techniques have been mainly developed with a single SDN controller which exposes a single point of failure as well as raises a scalability issue for large-scale networks in achieving both security and performance. The use of multiple SDN controllers has been proposed to ensure both performance and security of SDN-based MTD systems for large-scale networks; however, the effect of using multiple SDN controllers has not been investigated in the state-of-the-art research. In this paper, we propose the SDN based MTD architecture using multiple SDN controllers and validate their security effect (i.e., attack success probability) by implementing an IP shuffling MTD in a testbed using ONOS SDN controllers.

The imbalance relationship between FPGA hardware/software providers and FPGA users challenges the assurance of secure design on FPGAs. Existing efforts on FPGA security primarily focus on reverse engineering the downloaded FPGA configuration, retrieving the authentication code or crypto key stored on the embedded memory in FPGAs, and countermeasures for the security threats above. In this work, we investigate new security threats from malicious FPGA tools, and identify stealthy attacks that could occur during FPGA deployment. To address those attacks, we exploit the principles of moving target defense (MTD) and propose a FPGA-oriented MTD (FOMTD) method. Our method is composed of three defense lines, which are formed by an improved user constraint file, random selection of design replicas, and runtime submodule assembling, respectively. The FPGA emulation results show that the proposed FOMTD method reduces the hardware Trojan hit rate by 60% over the baseline, at the cost of 10.76% more power consumption.

The motivation behind Software-Defined Networking (SDN) is to allow services and network capabilities to be managed through a central control point. Moving Target Defense (MTD) introduces a constantly changing environment in order to delay or prevent attacks on a system. For the effective use of MTD, SDN can be used to help confuse the attacker from gathering legitimate information about the network. This paper investigates how SDN can be used for some network based MTD techniques and evaluate the benefits of integrating techniques in SDN and MTD. In the experiment, network assets are kept hidden from inside and outside attackers. Furthermore, the SDN controller is programed to perform IP mutation to keep changing real IP addresses of the underlying hosts by assigning each host a virtual IP address at a configured mutation rate to prevent attackers from stealing the real IP addresses or using fake IP addresses. The paper demonstrates experimental evaluation of the MTD technique using the Ryu controller and mininet. The results show that the MTD technique can be easily integrated into the SDN environment to use virtual IP addresses for hosts to reduce the chance of poisoning attacks.

Route randomization is an important research focus for moving target defense which seeks to proactively and dynamically change the forwarding routes in the network. In this paper, the difficulties of implementing route randomization in traditional networks are analyzed. To solve these difficulties and achieve effective route randomization, a novel route randomization approach is proposed, which is implemented by adding a mapping layer between routers' physical interfaces and their corresponding logical addresses. The design ideas and the details of proposed approach are presented. The effectiveness and performance of proposed approach are verified and evaluated by corresponding experiments.

Software-defined networking (SDN) is a recently developed approach to computer networking that brings a centralized orientation to network control, thereby improving network architecture and management. However, as with any communication environment that involves message transmission among users, SDN is confronted by the ongoing challenge of protecting user privacy. In this “Work in Progress (WIP)” research, we propose an SDN security model that applies the moving target defense (MTD) technique to protect communication links from sensitive data leakages. MTD is a security solution aimed at increasing complexity and uncertainty for attackers by concealing sensitive information that may serve as a gateway from which to launch different types of attacks. The proposed MTD-based security model is intended to protect user identities contained in transmitted messages in a way that prevents network intruders from identifying the real identities of senders and receivers. According to the results from preliminary experiments, the proposed MTD model has potential to protect the identities contained in transmitted messages within communication links. This work will be extended to protect sensitive data if an attacker gets access to the network device.

Moving Target Defense (MTD) is a research hotspot in the field of network security. Moving Target Network Defense (MTND) is the implementation of MTD at network level. Numerous related works have been proposed in the field of MTND. In this paper, we focus on the scope and area of MTND, systematically present the recent representative progress from four aspects, including IP address and port mutation, route mutation, fingerprint mutation and multiple mutation, and put forward the future development directions. Several new perspectives and elucidations on MTND are rendered.

Security issues in a Software Defined Network (SDN) environment like system vulnerabilities and intrusion attempts can pose a security risk for multi-tenant network managed by SDN. In this research work, Moving target defense (MTD)technique based on shuffle strategy - port hopping has been employed to increase the difficulty for the attacker trying to exploit the cloud network. Our research workMASON, considers the problem of multi-stage attacks in a network managed using SDN. SDN controller can be used to dynamically reconfigure the network and render attacker»s knowledge in multi-stage attacks redundant. We have used a threat score based on vulnerability information and intrusion attempts to identify Virtual Machines (VMs) in systems with high-security risk and implement MTD countermeasures port hopping to assess threat score reduction in a cloud network.

In this paper, a framework for Moving Target Defense is introduced. This framework bases on three pillars: network address mutation, communication stack randomization and the dynamic deployment of decoys. The network address mutation is based on the concept of domain generation algorithms, where different features are included to fulfill the system requirements. Those requirements are time dependency, unpredictability and determinism. Communication stack randomization is applied additionally to increase the complexity of reconnaissance activity. By employing communication stack randomization, previously fingerprinted systems do not only differ in the network address but also in their communication pattern behavior. And finally, decoys are integrated into the proposed framework to detect attackers that have breached the perimeter. Furthermore, attacker's resources can be bound by interacting with the decoy systems. Additionally, the framework can be extended with more advanced Moving Target Defense methods such as obscuring port numbers of services.

Protection of security-critical services, such as access-control reference monitors, is an important requirement in the modern era of distributed systems and services. The threat arises from hosting the service on a single server for a lengthy period of time, which allows the attacker to periodically enumerate the vulnerabilities of the service with respect to the server's configuration and launch targeted attacks on the service. In our work, we design and implement an efficient solution based on the moving "target" defense strategy, to protect security-critical services against such active adversaries. Specifically, we focus on implementing our solution for protecting the reference monitor service that enforces access control for users requesting access to sensitive resources. The key intuition of our approach is to increase the level of difficulty faced by the attacker to compromise a service by periodically moving the security-critical service among a group of heterogeneous servers. For this approach to be practically feasible, the movement of the service should be efficient and random, i.e., the attacker should not have a-priori information about the choice of the next server hosting the service. Towards this, we describe an efficient Byzantine fault-tolerant leader election protocol that achieves the desired security and performance objectives. We built a prototype implementation that moves the access control service randomly among a group of fifty servers within a time range of 250-440 ms. We show that our approach tolerates Byzantine behavior of servers, which ensures that a server under adversarial control has no additional advantage of being selected as the next active server.

Moving target defense(MTD) is a typical proactive cyber defense technology, which not only increases the difficulty of the attacker, but also reduces the damage caused by successful attacks. A number of studies have assessed the defensive effectiveness of MTD, but only focus on increasing the difficulty of attacks. No studies have been conducted to assess the impact of successful attacks on the network. In this paper, we propose a probability model that evaluates the impact of MTD against subsequent stages of complete attack process. The model quantify the probability distribution of the number of compromised hosts. The results of simulation show that MTD can reduce the number of compromised hosts, and attackers cannot control all hosts.