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Events for March 09, 2017
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CS Colloquium: David Naylor (CMU) - Privacy in the Internet (Without Giving up Everything Else)
Thu, Mar 09, 2017 @ 11:00 AM - 12:20 PM
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
Speaker: David Naylor, Carnegie Mellon University
Talk Title: Privacy in the Internet (Without Giving up Everything Else)
Series: CS Colloquium
Abstract: This lecture satisfies requirements for CSCI 591: Computer Science Research Colloquium.
Using the Internet inherently entails privacy risks. Each packet, potentially carrying information that users would rather keep private, is exposed to a network infrastructure operated by a number of third parties the user may not trust and likely cannot even identify. In some cases, the user may not even trust the recipient.
Techniques exist to protect user privacy, but they typically do so at the expense of other desirable properties. For example, anonymity services like Tor hide a packet's true sender, but weaken accountability by making it difficult for network administrators or law enforcement to track down malicious senders. Similarly, encryption hides application data from third parties, but prevents the use of middleboxes---devices that process packets in the network to improve performance (like caches) or security (like intrusion detection systems).
In this talk, I'll present techniques for managing these "Privacy vs. X" conflicts, including a new network architecture that re-thinks basic networking building blocks like packet source addresses and new secure communication protocols that explicitly balance data privacy with the benefits of middleboxes.
Biography: David is a Ph.D. student at Carnegie Mellon University, where he is advised by Peter Steenkiste. His primary research interests are computer networking, security, and privacy, but he is also interested in Web measurement and performance (http://isthewebhttp2yet.com and https://eyeorg.net). David received his B.S. from the University of Iowa in 2011, where he created the DDR inspired "Scrub Scrub Revolution," a handwashing training game for healthcare professionals. He is an NDSEG fellow and received an ACM SIGCOMM best paper award.
Host: CS Department
Location: Ronald Tutor Hall of Engineering (RTH) - 217
Audiences: Everyone Is Invited
Contact: Assistant to CS chair
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PhD Defense - Lian Liu
Thu, Mar 09, 2017 @ 02:00 PM - 04:00 PM
Thomas Lord Department of Computer Science
University Calendar
PhD Candidate: Lian Liu
Committee: Ming-Deh Huang (CS, chair), Sheldon Ross (ISE), Shang-Hua Teng (CS)
Title: Expander Cayley Graphs over Finite Strings and Pseudorandomness
Time: March 9 (Thursday) 2:00 - 3:30 pm.
Room: SAL 322 (i.e. the conference room on the 3rd floor of SAL)
Abstract:
We present an explicit construction of expander Cayley graphs over the direct sum of multiple copies of Z/pZ, where p is a prime number. So far as we know, our work is the first expander Cayley graph construction over such groups. Our construction consists of two phases. In the first phase, we consider Cayley graphs over the multiplicative groups of algebras over finite fields. We prove that for some well-chosen small generating sets which can be computed in polynomial time, the induced Cayley graphs are expanding. In the second phase, we construct an new Cayley graph by projecting the graph created in the first phase onto a direct component of the underlying group. We showed that the component on which the graph is projected is isomorphic to the direct sum of multiple copies of Z/pZ, and the resulting Cayley graph is a good expander. Interestingly, we found that many expander graphs whose degrees are not of any special forms can be explicitly constructed under this framework, which could be regarded as a tiny progress towards the open problem of constructing infinite families of Ramanujan graphs of every degree.
An special case of particular interest is when p equals 2. In this situation, the vertices of such a graph naturally correspond to bit strings of a fixed length, and each edge represents a transition between two bit strings under standard exclusive-or operation. As an application, we then propose a simple pseudorandom generator based on random walks on the graph. An important question is whether our pseudorandom generator is indistinguishable from a truly random source under probabilistic polynomial time attacks, which, however, remains open. In fact, constructing a secure and efficient pseudorandom generator has been an open problem since the birth of modern cryptography, whose solution may lead to huge breakthroughs in computer science. Therefore, our goal here is not addressing this problem, even partially. Instead, along with our discussion, we demonstrate that our expander Cayley graphs have some appealing features that all previous constructions do not have. These new features might bring a lot of potential topics for future research.
Location: Henry Salvatori Computer Science Center (SAL) - 322
Audiences: Everyone Is Invited
Contact: Lizsl De Leon
