Biblio

Recent attacks show that threats to cyber infrastructure are not only increasing in volume, but are getting more sophisticated. The attacks may comprise multiple actions that are hard to differentiate from benign activity, and therefore common detection techniques have to deal with high false positive rates. Because of the imperfect performance of automated detection techniques, responses to such attacks are highly dependent on human-driven decision-making processes. While game theory has been applied to many problems that require rational decisionmaking, we find limitation on applying such method on security games. In this work, we propose Q-Learning to react automatically to the adversarial behavior of a suspicious user to secure the system. This work compares variations of Q-Learning with a traditional stochastic game. Simulation results show the possibility of Naive Q-Learning, despite restricted information on opponents.

The human factor is often regarded as the weakest link in cybersecurity systems. The investigation of several security breaches reveals an important impact of human errors in exhibiting security vulnerabilities. Although security researchers have long observed the impact of human behavior, few improvements have been made in designing secure systems that are resilient to the uncertainties of the human element.

In this talk, we discuss several psychological theories that attempt to understand and influence the human behavior in the cyber world. Our goal is to use such theories in order to build predictive cyber security models that include the behavior of typical users, as well as system administrators. We then illustrate the importance of our approach by presenting a case study that incorporates models of human users. We analyze our preliminary results and discuss their challenges and our approaches to address them in the future.

Reliability block diagram (RBD) models are a commonly used reliability analysis method. For static RBD models, combinatorial solution techniques are easy and efficient. However, static RBDs are limited in their ability to express varying system state, dependent events, and non-series-parallel topologies. A recent extension to RBDs, called Dynamic Reliability Block Diagrams (DRBD), has eliminated those limitations. This tool paper details the RBD implementation in the M¨obius modeling framework and provides technical details for using RBDs independently or in composition with other M¨obius modeling formalisms. The paper explains how the graphical front-end provides a user-friendly interface for specifying RBD models. The back-end implementation that interfaces with the M¨obius AFI to define and generate executable models that the M¨obius tool uses to evaluate system metrics is also detailed.

Commercial networks today have diverse security policies, defined by factors such as the type of traffic they carry, nature of applications they support, access control objectives, organizational principles etc. Ideally, the wide diversity in SDN controller frameworks should prove helpful in correctly and efficiently enforcing these policies. However, this has not been the case so far. By requiring the administrators to implement both security as well as performance objectives in the SDN controller, these frameworks have made the task of security policy enforcement in SDNs a challenging one. We observe that by separating security policy enforcement from performance optimization, we can facilitate the use of SDN for flexible policy management. To this end, we propose Oreo, a transparent performance enhancement layer for SDNs. Oreo allows SDN controllers to focus entirely on a correct security policy enforcement, and transparently optimizes the dataplane thus defined, reducing path stretch, switch memory consumption etc. Optimizations are performed while guaranteeing that end-to-end reachability characteristics are preserved – meaning that the security policies defined by the controller are not violated. Oreo performs these optimizations by first constructing a network-wide model describing the behavior of all traffic, and then optimizing the paths observed in the model by solving a multi-objective optimization problem. Initial experiments suggest that the techniques used by Oreo is effective, fast, and can scale to commercial-sized networks.

Modern industrial control systems (ICSes) are increasingly adopting Internet technology to boost control efficiency, which unfortunately opens up a new frontier for cyber-security. People have typically applied existing Internet security techniques, such as firewalls, or anti-virus or anti-spyware software. However, those security solutions can only provide fine-grained protection at single devices. To address this, we design a novel software-defined networking (SDN) architecture that offers the global visibility of a control network infrastructure, and we investigate innovative SDN-based applications with the focus of ICS security, such as network verification and self-healing phasor measurement unit (PMU) networks. We are also conducting rigorous evaluation using the IIT campus microgrid as well as a high-fidelity testbed combining network emulation and power system simulation.

Modern industrial control systems (ICSes) are increasingly adopting Internet technology to boost control efficiency, which unfortunately opens up a new frontier for cyber-security. People have typically applied existing Internet security techniques, such as firewalls, or anti-virus or anti-spyware software. However, those security solutions can only provide fine-grained protection at single devices. To address this, we design a novel software-defined networking (SDN) architecture that offers the global visibility of a control network infrastructure, and we investigate innovative SDN-based applications with the focus of ICS security, such as network verification and self-healing phasor measurement unit (PMU) networks. We are also conducting rigorous evaluation using the IIT campus microgrid as well as a high-fidelity testbed combining network emulation and power system simulation.

We rely on network infrastructure to deliver critical services and ensure security. Yet networks today have reached a level of complexity that is far beyond our ability to have confidence in their correct behavior – resulting in significant time investment and security vulnerabilities that can cost millions of dollars, or worse. Motivated by this need for rigorous understanding of complex networks, I will give an overview of our or Science of Security lablet project, A Hypothesis Testing Framework for Network Security.

First, I will discuss the emerging field of network verification, which transforms network security by rigorously checking that intended behavior is correctly realized across the live running network. Our research developed a technique called data plane verification, which has discovered problems in operational environments and can verify hypotheses and security policies with millisecond-level latency in dynamic networks. In just a few years, data plane verification has moved from early research prototypes to production deployment. We have built on this technique to reason about hypotheses even under the temporal uncertainty inherent in a large distributed network. Second, I will discuss a new approach to reasoning about networks as databases that we can query to determine answers to behavioral questions and to actively control the network. This talk will span work by a large group of folks, including Anduo Wang, Wenxu an Zhou, Dong Jin, Jason Croft, Matthew Caesar, Ahmed Khurshid, and Xuan Zou.

In this paper we explore the differential perceptions of cybersecurity professionals and general users regarding access rules and passwords. We conducted a preliminary survey involving 28 participants: 15 cybersecurity professionasl and 13 general users. We present our preliminary findings and explain how such survey data might be used to improve security in practice. We focus on user fatigue with access rules and passwords.

We present a technique for bounded invariant verification of nonlinear networked dynamical systems with delayed interconnections. The underlying problem in precise boundedtime verification lies with computing bounds on the sensitivity of trajectories (or solutions) to changes in initial states and inputs of the system. For large networks, computing this sensitivity
with precision guarantees is challenging. We introduce the notion of input-to-state (IS) discrepancy of each module or subsystem in a larger nonlinear networked dynamical system. The IS discrepancy bounds the distance between two solutions or trajectories of a module in terms of their initial states and their inputs. Given the IS discrepancy functions of the modules, we show that it is possible to effectively construct a reduced (low dimensional) time-delayed dynamical system, such that the trajectory of this reduced model precisely bounds the distance between the trajectories of the complete network with changed initial states. Using the above results we develop a sound and relatively complete algorithm for bounded invariant verification of networked dynamical systems consisting of nonlinear modules interacting through possibly delayed signals. Finally, we introduce a local version of IS discrepancy and show that it is possible to compute them using only the Lipschitz constant and the Jacobian of the dynamic function of the modules.
 

While there have been various studies identifying and classifying Android malware, there is limited discussion of the broader class of apps that fall in a gray area. Mobile grayware is distinct from PC grayware due to differences in operating system properties. Due to mobile grayware’s subjective nature, it is difficult to identify mobile grayware via program analysis alone. Instead, we hypothesize enhancing analysis with text analytics can effectively reduce human effort when triaging grayware. In this paper, we design and implement heuristics for seven main categories of grayware.We then use these heuristics to simulate grayware triage on a large set of apps from Google Play. We then present the results of our empirical study, demonstrating a clear problem of grayware. In doing so, we show how even relatively simple heuristics can quickly triage apps that take advantage of users in an undesirable way.