Attack-defense trees

Attack-defense trees are a novel methodology for graphical security modelling and assessment. They extend the well- known formalism of attack trees by allowing nodes that represent defensive measures to appear at any level of the tree. This enlarges the modelling capabilities of attack trees and makes the new formalism suitable for representing interactions between an attacker and a defender. Our formalization supports different semantical approaches for which we provide usage scenarios. We also formalize how to quantitatively analyse attack and defense scenarios using attribute

Quantitative Security Risk Modeling and Analysis with RisQFLan

Domain-specific quantitative modeling and analysis approaches are fundamental in scenarios in which qualitative approaches are inappropriate or unfeasible. In this paper, we present a tool-supported approach to quantitative graph-based security risk modeling and analysis based on attack-defense trees. Our approach is based on QFLan, a successful domain-specific approach to support quantitative modeling and analysis of highly configurable systems, whose domain-specific components have been decoupled to facilitate the instantiation of the QFLan approach in the domain of graph-based security risk modeling and analysis. Our approach incorporates distinctive features from three popular kinds of attack trees, namely enhanced attack trees, capabilities-based attack trees and attack countermeasure trees, into the domain-specific modeling language. The result is a new framework, called RisQFLan, to support quantitative security risk modeling and analysis based on attack-defense diagrams. By offering either exact or statistical verification of probabilistic attack scenarios, RisQFLan constitutes a significant novel contribution to the existing toolsets in that domain. We validate our approach by highlighting the additional features offered by RisQFLan in three illustrative case studies from seminal approaches to graph-based security risk modeling analysis based on attack trees

Defense against Insider Threat: a Framework for Gathering Goal-based Requirements

Insider threat is becoming comparable to outsider threat in frequency of security events. This is a worrying situation, since insider attacks have a high probability of success because insiders have authorized access and legitimate privileges. Despite their importance, insider threats are still not properly addressed by organizations. We contribute to reverse this situation by introducing a framework composed of a method for identification and assessment of insider threat risks and of two supporting deliverables for awareness of insider threat. The deliverables are: (i) attack strategies structured in four decomposition trees, and (ii) a matrix which correlates defense strategies, attack strategies and control principles. The method output consists of goal-based requirements for the defense against insiders

Managing Security Risks Using Attack-Defense Trees

Nagu mujal valdkondades, kasvab tänapäeval vajadus turvalisuse järele, nii ka ärimaailmas. Käesolev magistritöö üritab seda probleemi lahendada kasutades riskianalüüsi diagrammi mudelit, mida inglise keeles nimetatakse Attack Tree.ISSRM (Information System Security Risk Managment) on mudel, mis käsitleb kõiki olulisi riskianalüüsi aspekte, on lihtsalt arusaadav ja annab olukorrast kiire ülevaate. Laiendustena on olemas mõned sellised riskianalüüsi diagrammid, kuid ükski neist pole võimeline käsitlema kõiki võimalikke ohuolukordi. See paneb diagrammi kasutamisele piirid, kuna ei arvesta võimalikke vastumeetmeid ohtudele, ega ohuallika profiili.Antud magistritöö pakub sellele probleemile kolmeosalist lahendust.1. luua sild riskianalüüsi puu osast, mis käsitleb kaitsetehnikaid (Attack Defence Tree), kuni ISSRM mudelini;2. arvestades minevikus ette tulnud riske, riskifaktorite tõenäolisuse ja nendega seotud kulutuste mõõteparameetrite väljatöötamine;3. tööriista kasutamine, mis on välja töötatud antud riskianalüüsipuu abil.Selliselt loodud sild aitab leida veel avastamata aspekte riskianalüüsi puus. Lisades sellise laienduse, on riskianalüüsi puu täielikum ja muudab ISSRM-i mudeli mitmekülgsemaks. Selleks, et riske paremini analüüsida, on kasulik arvestada ka minevikus ette tulnud ohte ning neid matemaatiliselt uurida tõenäolisuse aspektist, et minimeerida sarnaste ohuolukordade taastekkimise tõenäosust. Magistritöö tegemise käigus välja töötatud tööriist (Aligned Attack-Defense Tree or A-ADTree) on võimekam riski tõenäosusele hinnangu andmisel teistest juba olemasolevatest versioonidest. Antud tööriist annab riskianalüüsi hindajatele rohkem võimalusi võimalike ohuolukordade lahendamiseks ja ennetamiseks. Kuna siin kasutatud modelleerimiskeeled on juba sobitatud ISSRM mudeliga, võimaldab antud töös välja töötatud laiendus luua enam seoseid selle ning teiste modelleerimiskeelte (nt Secure BPMN, Misuse-case diagram, Secure TROPOS, and Mal-Activity diagram) vahel ka tulevikus.Nowadays there is an increasing demand for answering the security needs in systematic ways. The In this thesis, we have addressed risk management using Attack Tree.Information System Security Risk Management (ISSRM) is a model which covers all the important concepts in risk management. Also, attack trees are simple and efficient tools for showing the risks. There are few extensions of attack trees, but none of them covers all risk concepts. The said problem limited the usage of attack tree model since it does not consider important measures such as countermeasures, or threat agent’s profile.The contribution to resolve the problem in this thesis includes three steps. Obtaining an alignment from Attack-Defense trees to ISSRM. Measurement of the metrics of the nodes of tree using historical dataImplementation of a tool based on obtained tree.Using the alignment, we have detected the uncovered concepts in Attack-Defense tree. Then we tried to add these concepts to the current Attack-Defense tree. Therefore, the new Attack-Defense tree (called Aligned Attack-Defense tree or A-ADTree) covers most important concepts of ISSRM. In order to measure the risk, we have proposed a mathematical model to evaluate the probability of the nodes in the tree, based on historical data. Then, implemented tool helps to materialize the effect of threat agent’s profile, and countermeasures on the risks. The result of implemented tool shows, the obtained A-ADTree has more capabilities (in the evaluation of the probability of risk) in comparison to previous versions. This solution is capable of giving more hints for the project managers when they are deciding about possible solutions in industries. Additionally, this alignment helps to obtain another alignment between A-ADTree and the other modeling languages in future, since these modeling languages are already aligned to ISSRM

Using attack-defense trees to analyze threats and countermeasures in an ATM: a case study

Securing automated teller machines (ATMs), as critical and complex infrastructure, requires a precise understanding of the associated threats. This paper reports on the application of attack-defense trees to model and analyze the security of ATMs.We capture the most dangerous multi-stage attack scenarios applicable to ATM structures, and establish a practical experience report, where we re ect on the process of modeling ATM threats via attack-defense trees. In particular, we share our insights into the benets and drawbacks of attack-defense tree modeling, as well as best practices and lessons learned

A Probabilistic Framework for Security Scenarios with Dependent Actions

This work addresses the growing need of performing meaningful probabilistic analysis of security. We propose a framework that integrates the graphical security modeling technique of attack–defense trees with probabilistic information expressed in terms of Bayesian networks. This allows us to perform probabilistic evaluation of attack–defense scenarios involving dependent actions. To improve the efficiency of our computations, we make use of inference algorithms from Bayesian networks and encoding techniques from constraint reasoning. We discuss the algebraic theory underlying our framework and point out several generalizations which are possible thanks to the use of semiring theory