124 research outputs found
On a Generic Security Game Model
To protect the systems exposed to the Internet against attacks, a security
system with the capability to engage with the attacker is needed. There have
been attempts to model the engagement/interactions between users, both benign
and malicious, and network administrators as games. Building on such works, we
present a game model which is generic enough to capture various modes of such
interactions. The model facilitates stochastic games with imperfect
information. The information is imperfect due to erroneous sensors leading to
incorrect perception of the current state by the players. To model this error
in perception distributed over other multiple states, we use Euclidean
distances between the outputs of the sensors. We build a 5-state game to
represent the interaction of the administrator with the user. The states
correspond to 1) the user being out of the system in the Internet, and after
logging in to the system; 2) having low privileges; 3) having high privileges;
4) when he successfully attacks and 5) gets trapped in a honeypot by the
administrator. Each state has its own action set. We present the game with a
distinct perceived action set corresponding to each distinct information set of
these states. The model facilitates stochastic games with imperfect
information. The imperfect information is due to erroneous sensors leading to
incorrect perception of the current state by the players. To model this error
in perception distributed over the states, we use Euclidean distances between
outputs of the sensors. A numerical simulation of an example game is presented
to show the evaluation of rewards to the players and the preferred strategies.
We also present the conditions for formulating the strategies when dealing with
more than one attacker and making collaborations.Comment: 31 page
Construction of dynamic stochastic simulation models using knowledge-based techniques
Over the past three decades, computer-based simulation models have proven themselves to be cost-effective alternatives to the more structured deterministic methods of systems analysis. During this time, many techniques, tools and languages for constructing computer-based simulation models have been developed. More recently, advances in knowledge-based system technology have led many researchers to note the similarities between knowledge-based programming and simulation technologies and to investigate the potential application of knowledge-based programming techniques to simulation modeling. The integration of conventional simulation techniques with knowledge-based programming techniques is discussed to provide a development environment for constructing knowledge-based simulation models. A comparison of the techniques used in the construction of dynamic stochastic simulation models and those used in the construction of knowledge-based systems provides the requirements for the environment. This leads to the design and implementation of a knowledge-based simulation development environment. These techniques were used in the construction of several knowledge-based simulation models including the Advanced Launch System Model (ALSYM)
Nickel hydrogen battery expert system
The Hubble Telescope Battery Testbed at MSFC uses the Nickel Cadmium (NiCd) Battery Expert System (NICBES-2) which supports the evaluation of performance of Hubble Telescope spacecraft batteries and provides alarm diagnosis and action advice. NICBES-2 provides a reasoning system along with a battery domain knowledge base to achieve this battery health management function. An effort is summarized which was used to modify NICBES-2 to accommodate Nickel Hydrogen (NiH2) battery environment now in MSFC testbed. The NICBES-2 is implemented on a Sun Microsystem and is written in SunOS C and Quintus Prolog. The system now operates in a multitasking environment. NICBES-2 spawns three processes: serial port process (SPP); data handler process (DHP); and the expert system process (ESP) in order to process the telemetry data and provide the status and action advice. NICBES-2 performs orbit data gathering, data evaluation, alarm diagnosis and action advice and status and history display functions. The adaptation of NICBES-2 to work with NiH2 battery environment required modification to all of the three component processes
Development of nickel hydrogen battery expert system
The Hubble Telescope Battery Testbed employs the nickel-cadmium battery expert system (NICBES-2) which supports the evaluation of performances of Hubble Telescope spacecraft batteries and provides alarm diagnosis and action advice. NICBES-2 also provides a reasoning system along with a battery domain knowledge base to achieve this battery health management function. An effort to modify NICBES-2 to accommodate nickel-hydrogen battery environment in testbed is described
Comparing Agent Software Development Methodologies Using the Waterfall Model
This paper explores three widely published agent-based software development methodologies, Multiagent Systems Engineering Methodology (MaSE), Prometheus, and Tropos, using the traditional Waterfall model of software engineering as a baseline. Differences between the methodologies are examined and gaps between the agent-based methodologies and the Waterfall approach are identified
Security in the Cloud Based Systems: Structure and Breaches
Abstract-Cloud based systems(CBSs) are increasing in the computing world. These systems derive their complexity due to both the disparate components and the diverse stake holders involved in them. The component wise security alone does not solve the problem of securing CBSs, but the stakeholder's computational space spanning across many components of the CBS, needs to be secured too. There have been initial attempts to model the security of the cloud in terms of securing stakeholder's computational space. Some recent attempts formally model the CBS as modularized actor models, using rewriting & equational logic based modeling languages. Building on these works we present a framework for building executable models of CBSs for security analyses. We illustrate its validity showing how the recent security breaches and security solutions can be modeled and analyzed using this framework
Analysis of Monitoring Tools for Java Applications
Abstract. Runtime Monitoring is performed during the execution of software to detect anomalies in them. Currently several tools are available that help in developing the monitors. We analyze the prominent monitoring tools available for Java applications based on two features, the properties that can be monitored using these tools and the specification language used to specify the monitorable properties. The analysis performed will help the users and developers better evaluate the characteristics of different monitoring tools available in order to select the one suitable for their application
On Modeling and Analysis of MIMO Wireless Mesh Networks with Triangular Overlay Topology
Multiple input multiple output (MIMO) wireless
mesh networks (WMNs) aim to provide the last-mile broadband
wireless access to the Internet. Along with the algorithmic development
for WMNs, some fundamental mathematical problems
also emerge in various aspects such as routing, scheduling, and
channel assignment, all of which require an effective mathematical
model and rigorous analysis of network properties. In
this paper, we propose to employ Cartesian product of graphs
(CPG) as a multichannel modeling approach and explore a
set of unique properties of triangular WMNs. In each layer of
CPG with a single channel, we design a node coordinate scheme
that retains the symmetric property of triangular meshes and
develop a function for the assignment of node identity numbers
based on their coordinates. We also derive a necessary-sufficient
condition for interference-free links and combinatorial formulas
to determine the number of the shortest paths for channel
realization in triangular WMNs
ADAPT: A Game Inspired Attack-Defense And Performance Metric Taxonomy
Abstract. Game theory has been researched extensively in network security demonstrating an advantage of modeling the interactions between attackers and defenders. Game theoretic defense solutions have continuously evolved in most recent years. One of the pressing issues in composing a game theoretic defense system is the development of consistent quantifiable metrics to select the best game theoretic defense model. We survey existing game theoretic defense, information assurance, and risk assessment frameworks that provide metrics for information and network security and performance assessment. Coupling these frameworks, we propose a game theoretic approach to attack-defense and performance metric taxonomy (ADAPT). ADAPT uses three classifications of metrics: (i) Attacker, (ii) Defender (iii) Performance. We proffer ADAPT with an attempt to aid game theoretic performance metrics. We further propose a game decision system (GDS) that uses ADAPT to compare competing game models. We demonstrate our approach using a distributed denial of service (DDoS) attack scenario. Keywords: Game Theory, Taxonomy, Security Management INTRODUCTION Game theory has received increased attention from network security researchers, investigating defense solutions. The game theory approach has the advantage of modeling the interactions between attackers and defenders, where players have the ability to analyze other player's behavior. This may enable an administrator to develop better strategic defenses for the system. For instance, when there are many actions available to the attacker and defender, it becomes difficult to develop solution strategies. Hamilton, et al. [1] outlined the areas of game theory which are relevant to information warfare using course of actions with predicted outcomes and what-if scenarios. Jiang, et al. In this paper, we attempt to address limitations in research through the proposed game theoretic attack-defense and performance metric taxonomy (ADAPT), which is a taxonomy of game related metrics. We define a game as the interactions between two players with conflicting goals. In our case these players are the attacker (hacker) and system administrator (defender). Game metrics are a set of tools which are used to measure the various kinds of impact a game model has on each of its players. We classify these game metrics based on their impact on attacker, defender, and the performance of the game model on the system which is being run. Prior research has shown, with the use of game theory, how the interaction should take place based on the strategy and the strategy selected from the game model. In this traditional scenario one game model is assessed relative to a particular attack. He, et al. [6] proposed a Game Theoretical Attack-Defense Model (GTADM), similar to ADAPT, that quantifies the probability of threats in constructing a risk assessment framework. We extend these general game theory steps and concepts proposed in He, et al. [6] with the use of ADAPT being able to assess competing game models and select the game model which is suitable for defense. This provides a defender with a preliminary view of multiple game models associated to a particular attack
Association between gastrointestinal events and compliance with osteoporosis therapy
AbstractPurposeThe aim of this study was to estimate the rate of gastrointestinal (GI) events, and association between GI events and compliance with osteoporosis therapy among osteoporotic women.MethodsA retrospective cohort study using a large administrative claims database in the United States from 2001 through 2010 was conducted. We studied women ≥55years old who were continuously enrolled in a health plan for at least 2years, a baseline year before and a follow-up year after the date of the first prescription of oral bisphosphonate as the first oral osteoporosis treatment. Compliance with osteoporosis therapy was measured using the medication possession ratio (MPR), with compliance defined as MPR ≥0.8. Multivariate logistic regression was used to assess the association between occurrence of GI events and compliance with osteoporosis therapy after controlling for demographic and clinical characteristics.ResultsA sample consisting of 75,593 women taking at least one oral bisphosphonate with mean (SD) age of 64 (8) years was identified. A total of 21,142 (28%) patients experienced at least one GI event during the follow-up period. Only 31,306 (41%) patients were compliant with osteoporosis therapy. Patients who experienced GI events after initiation of oral bisphosphonates were 29% less likely to adhere to osteoporosis therapy as compared to patients who did not experience GI events (odds ratio [95% CI], 0.71 [0.69–0.74]; P<.001).ConclusionsLess than half of the patients were compliant with osteoporosis therapy within one year after initiating oral bisphosphonates, and the likelihood of compliance was significantly lower by 29% among women with GI events
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