An approach to incorporating uncertainty in network security analysis

Attack graphs used in network security analysis are analyzed to determine sequences of exploits that lead to successful acquisition of privileges or data at critical assets. An attack graph edge corresponds to a vulnerability, tacitly assuming a connection exists and tacitly assuming the vulnerability is known to exist. In this thesis, we explore use of {\em uncertain graphs} to extend the paradigm to include lack of certainty in connection and/or existence of a vulnerability. We extend the standard notion of uncertain graph (where the existence of each edge is probabilistically independent) however, as significant correlations on edge existence probabilities exist in practice, owing to common underlying causes for disconnectivity and/or presence of vulnerabilities. Our extension describes each edge probability as a Boolean expression of independent indicator random variables. This thesis (i) shows that this formalism is maximally descriptive in the sense that it can describe any joint probability distribution function of edge existence, (ii) shows that when these Boolean expressions are monotone then we can easily perform uncertainty analysis of edge probabilities, and (iii) uses these results to model a partial attack graph of the Stuxnet worm and a small enterprise network and to answer important security-related questions in a probabilistic manner.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2019

Author dc:creator

• Nguyen, Hoang Hai

Contributors dc:contributor

• Nicol, David M.

• network security, uncertainty, attach graph, reachability

Statement dc:rights

• Copyright 2018 Hoang Hai Nguyen

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/102416

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/102416