[Colloq] Talk: Cristina Nita-Rotaru - Noon January 27th 108 WVH - Beyond Byzantine Agreement: Increasing Network Resiliency to Compromises by Optimally Assigning Diverse Variants to Routing Nodes

[Biron, Jessica]

Cristina Nita-Rotaru
Purdue University

Tuesday January 27th
Noon, 108 WVH

Title:

Beyond Byzantine Agreement:
Increasing Network Resiliency to Compromises
by Optimally Assigning Diverse Variants to Routing Nodes


Abstract:

Current computing and networking environments make it difficult
to provide a secure perimeter where some components are isolated
while strict access control and communication policies are enforced.
As a result, many protocols were designed assuming that some of the
participants can be compromised and exhibit malicious behavior. These
protocols provide correct behavior to correct participants under the
assumption that no more than a fraction of nodes are compromised,
assumption difficult to meet in practice in an homogeneous environment,
where any vulnerability found against a node could be used to compromise
all nodes. Heterogeneity (i.e diversity) can be achieved by using different
software implementations, or different policies and administrative personnel.
However, with few variants, the choice of assignment of variants to nodes
is critical to the overall network resiliency.

This talk describes how diversity among nodes can be used to increase
network resilience. We first define the Diversity Assignment Problem
(DAP) -- finding the variant placement to nodes that maximizes expected
client connectivity --  and show how to compute the optimal solution in
medium-size networks. We also present a greedy approximation to DAP
that scales well to large networks. We then show a solution for a
variant of the DAP that optimizes for a different application relevant
metric such as connected component.   Our solution evaluated on a real
topology obtained from a cloud networking provider shows that a high
level of overall network resiliency can be obtained even from variants
that are weak on their own.




Bio:

Cristina Nita-Rotaru is an Associate Professor in the Department of Computer Science
at Purdue University where she established the Dependable and Secure Distributed
Systems Laboratory (DS2), and is a member of the Center for Education and Research
in Information Assurance and Security (CERIAS). Her research lies at the intersection
of information security, distributed systems, and computer networks. The overarching
goal of her work is designing and building practical distributed systems and network
protocols that are robust to failures and attacks while coping with the resource
constraints existent in computing systems and networks.

Cristina Nita-Rotaru is a recipient of the NSF Career Award in 2006.  She is also a
recipient of the Purdue Teaching for Tomorrow Award in 2007, Purdue Excellence in
Research Award, Seeds for Success in 2012, Purdue College of Science Research Award
in 2013. She has served on the Technical Program Committee of numerous conferences
in security, networking, and distributed systems.  She served as an Assistant Director
for CERIAS (2011 - 2013). She was an Associate Editor for Elsevier Computer Communications
(2008 - 2011), Elsevier Computer Networks (2012 - 2014), IEEE Transactions on Computers
(2011 - 2014), and ACM Transactions on Information Systems Security (2009 - 2013). She
is currently an Associate Editor for IEEE Transactions on Mobile Computing and IEEE
Transactions on Dependable and Secure Systems.

http://homes.cerias.purdue.edu/~crisn/
http://ds2.cs.purdue.edu