Emanuele Galli

Federated Agent-based Modeling and Simulation Approach to Study Interdependencies in IT Critical Infrastructures

Agent-based modeling and simulation (ABMS) is one of the more promising simulation techniques to study the interdependencies in critical infrastructures. Moreover, federated simulation has two relevant properties, simulation models reuse and expertise sharing, that could be exploited in a multi-sectorial field, such as critical infrastructure protection. In this paper we propose a new methodology which exploits the benefit of both ABMS and Federated simulation, to study interdependencies in critical infrastructures. First of all we discus advantages of federated agent-based modeling and difficulties in implementing a Federated ABMS framework. To demonstrate the relevance of our solution we propose an example driven approach that poses the attention on critical information infrastructure. We have also implemented a Federated ABMS framework, which federate Repast, an agent-based simulation engine and OMNeT++ an IT systems and communication networks modeling and simulation environment. A selection of simulation results shown how Federated ABMS could shed light on system interdependencies and how it helps in quantifying them.

SMS-Watchdog: Profiling Social Behaviors of SMS Users for Anomaly Detection

With more than one trillion mobile messages delivered worldwide every year, SMS has been a lucrative playground for various attacks and frauds such as spamming, phishing and spoofing. These SMS-based attacks pose serious security threats to both mobile users and cellular network operators, such as information stealing, overcharging, battery exhaustion, and network congestion. Against the backdrop that approaches to protecting SMS security are lagging behind, we propose a lightweight scheme called SMS-Watchdog that can detect anomalous SMS behaviors with high accuracy. Our key contributions are summarized as follows: (1) After analyzing an SMS trace collected within a five-month period, we conclude that for the majority of SMS users, there are window-based regularities regarding whom she sends messages to and how frequently she sends messages to each recipient. (2) With these regularities, we accordingly propose four detection schemes that build normal social behavior profiles for each SMS user and then use them to detect SMS anomalies in an online and streaming fashion. Each of these schemes stores only a few states (typically, at most 12 states) in memory for each SMS user, thereby imposing very low overhead for online anomaly detection. (3) We evaluate these four schemes and also two hybrid approaches with realistic SMS traces. The results show that the hybrid approaches can detect more than 92% of SMS-based attacks with false alarm rate 8.5%, or about two thirds of the attacks without any false alarm, depending on their parameter settings.

Metrics For Quantifying Interdependencies

The quantification of interdependencies is a, major challenge when attempting to analyze the behavior of critical infrastructures. This paper presents a taxonomy of interdependency quantification metrics based on their information content, decision support and risk analysis capabilities, and computational costs. The paper also discusses a systematic approach for computing metrics and performance indices that measure the effectiveness of strategies designed to enhance critical infrastructure protection and resilience. A case study is used to illustrate the computation of the metrics and performance indices, and their application to the analysis of critical infrastructure interdependencies.

Designing systems for large-scale, discrete-event simulations: Experiences with the FastTrans parallel microsimulator

We describe the various aspects involved in building FastTrans, a scalable, parallel microsimulator for transportation networks that can simulate and route tens of millions of vehicles on real-world road networks in a fraction of real time. Vehicular trips are generated using agent-based simulations that provide realistic, daily activity schedules for a synthetic population of millions of intelligent agents. We use parallel discrete-event simulation techniques and distributed-memory algorithms to scale these simulations to over one thousand compute nodes. We present various optimizations for speeding up simulation execution times, including (i) a set of routing algorithms such as variations of Dijkstras shortest path algorithm and heuristic-based A⋆ search, and (ii) a number of different partitioning schemes for load balancing, including geographic partitioning (that assigns simulation entities that are geographically close by to the same processor) and scattering (that assigns geographically close by entities to different processors). Our main findings include: (i) A⋆ significantly outperforms other routing algorithms while computing near-optimal paths; (ii) surprisingly, scattering outperforms more sophisticated partitioning schemes by achieving near-perfect load-balancing. With optimized routing and partitioning, FastTrans is able to simulate a full 24 hour work-day in New York — involving over one million road links and approximately 25 million vehicular trips — in less than one hour of wall-clock time on a 512-node cluster.

HLA-OMNET++: An HLA Compliant Network Simulator

An approach to the modeling of Critical Infrastructure can be the integration of already implemented and heterogeneous simulators. In this way the model builder can concentrate more on the modeling of interdependencies between heterogeneus infrastructure than on the developing of a huge and unique simulator. The HLA standard is probably one of the more common technique to reach such goal. We present the architecture and implementation of the HLAOMNet++:an HLA-1516 network simulator used to simulate the communication network infrastructure.

Modeling and Simulation of Complex Interdependent Systems: A Federated Agent-Based Approach

Critical Interdependent Infrastructures are complex interdependent systems, that if damaged or disrupted can seriously compromise the welfare of our society. This research, part of the CRESCO project, faces the problem of interdependent critical infrastructures modeling and simulation proposing an agent-based solution. The approach we put forward, named Federated ABMS, relies on discrete agent-based modeling and simulation and federated simulation. Federated ABMS provides a formalism to model compound complex systems, composed of interacting systems, as federation of interacting agents and sector specific simulation models. This paper describes the formal model as well it outlines the steps that characterize the Federated ABMS methodology, here applied to a target system, composed of a communication network and of a power grid. Moreover we conclude the paper with a thorough discussion of implementation issues.

Federated Agent Based Modeling and Simulation: an Approach for Complex Critical Systems Analysis

What we propose is a framework, based on federated simulation and ABMS, which has the goal to support the correct modeling, understanding and quantification of complex critical systems interdependencies and behavior. The advantages of the proposed solution are: 1) the complex system is modeled using a bottom-up approach, form the single components to the whole system (ABMS capability); 2) specific sector simulation models can be reused (federated simulation capabilities); 3) large scale simulation is supported (federated simulation capabilities). Federated ABMS exploits the ABMS capabilities, to model the whole complex system as a set of interacting agents, and the federated simulation capabilities, to reuse existing models which will help in modeling agents behavior at different level of abstraction. ABMS is used to provide an high level model of the system, representing the infrastructures, the active entities and the environment as interacting agents. The behavior of each agent is modeled by using existing sector specific simulation models.

Macro and Micro Agent-Based Modeling and Simulation of Critical Infrastructures

All individuals of every nation rely on many infrastructures that provide us all essential services to support our welfare, economy and quality of life. These critical infrastructures are complex and interdependent systems and a comprehensive study of their dynamic is mainly addressed using simulative approaches. In this paper we discuss advantages, drawbacks, cost and scalability of two agent based methodologies (macro-agent based and micro-agent based simulation), and related implementations, to model and simulate interdependent critical infrastructures.

MobileOnRealEnvironment-GIS: A Federated Mobile Network Simulator of Mobile Nodes on Real Geographic Data

In this paper we introduce MORE-GIS, a simulatorfor the simulation of mobile nodes connected to wiredand wireless network for the study of Critical Infrastructuresinterdependencies. MORE-GIS is based on agent based simulationapproach and HLA architecture. Every node is an agentthat represents a person. Agents are connected to Internetgenerating a certain amount of traffic and can move to a newgeographic position. Movements are simulated using GIS dataof roads and junctions. Every person selects the path usingthe Dijkstra’s algorithm. Actually we use Repast Symphonyframework for the agent based simulation and the MobilityFramework of OMNeT++ for the simulation of the wirelessand wired communication network. They are synchronized andexchange information using the HLA architecture.