Upcoming Public Talks

Title: TBA

Thomas Dietterich — Thu, 11 Feb 2010 15:30:00 -0800

Distinguished Lecture Series - A Cryptic Letter to Thomas Jefferson

Lawren Smithline — Tue, 26 Jan 2010 16:00:00 -0800

On Christmas Day, 1801, Thomas Jefferson received a letter from University of Pennsylvania professor Robert Patterson. The last page of the letter was written using the cipher described in the earlier pages, and Patterson withheld the key, writing, "I may safely defy the united ingenuity of the whole human race to decypher [such writing] to the end of time." The first successful cryptanalysis was done by me in 2007.

I will describe Patterson's cipher, its place in history, and its solution.

The cipher manuscript is available from the Library of Congress at http://memory.loc.gov/master/mss/mtj/mtj1/025/0300/0304.jpg.

Biography

Lawren Smithline received his Ph. D. from University of California, Berkeley, writing a thesis on p-adic modular forms. After several years at Cornell University, and a shift in focus to computational biology, he moved to the Center for Communications Research, where he continues to work on a spectrum of applied and theoretical math problems.

This talk is cosponsored by the Department of Mathematics.

Securing Network Access in Wireless Sensor Networks Supporting Industrial Control System

Kun Sun — Thu, 14 Jan 2010 15:30:00 -0800

Industrial control systems (ICSs) are crucial to the operation of the U.S. critical infrastructures, such as energy, water treatment, agriculture and food, and transportation systems. Recent advances in wireless sensor networks leverage the capabilities of the existing monitoring and control infrastructure in the ICSs. However, it is difficult to define and control boundaries and interactions between sensor nodes in wireless sensor networks. Threats to control systems can come from numerous sources, including hostile governments, terrorist groups, malicious intruders, complexities, accidents, natural disasters as well as malicious or accidental actions by insiders.

We developed and implemented a prototype secure network access system for wireless sensor networks that support ICSs. This system can provide node authentication, packet authentication, packet integrity, and packet confidentiality using standardized cryptosystems. The system consists of three stages. In the Network Admission Control stage, when new sensor nodes are added into an existing sensor network, they can generate a pairwise secret key with an admission controller using the self-certified Elliptic Curve Diffie-Hellman (ECDH) key exchange protocol. We developed a polynomial-based weak authentication scheme to mitigate potential Denial of Service (DoS) attacks against the self-certified ECDH protocol. In the Network Access Control stage, we implemented symmetric key cryptography with hardware security support in the radio components on common sensor platforms. We enforced secure and efficient network access by employing a network-wide secret key, which is only known to eligible nodes, to authenticate all the packets transmitted in the network. In the Network Access Maintenance stage, to remove the compromised nodes from the network, we designed and implemented stateless group key update schemes to update the secret key shared by all the eligible nodes.

Biography

Dr. Kun Sun is a senior Research Scientist in Intelligent Automation Inc. at Rockville, Maryland. He leads the research on network and systems security. He has won a number of research awards (1.5 Million in total) from government agencies like DoD, DHS, and NIST. He serves as technical lead for projects including secure network access in industrial control system, security analysis using security metrics, secure database system in ad-hoc networks, trusted query and trusted routing in wireless sensor networks, and DoS mitigation in wireless networks.

Can Lisp Be Saved?

Drew McDermott — Mon, 30 Nov 2009 16:00:00 -0800

Lisp is, as its inventor, John McCarthy once observed, "a local maximum in the space of programming languages," and to some fans it seems like it might even be the global maximum. However, it has one glaring weakness: an inadequate type system. The type system, by contrast with the rest of the language, has clumsy syntax and obscure semantics. Plus, the practices of Lisp programmers tend to be based on the assumption that no one's keeping tabs on you when you change or test the value of a variable. As a consequence, the Lisp compiler provides almost no useful information; most debugging occurs at run time.

Unfortunately, languages with good type systems, such as ML and Haskell, have evolved away from Lisp's wonderful XML-like syntax. They rely too heavily on Currying as a representation for multi-parameter functions. There is practically no such thing as an ML function that takes an indefinite number of arguments. When you try to create a type system able to handle this essential Lisp feature, you run into some very interesting and obscure issues.

Fortunately, recent research in type systems has begun to fill in these gaps. I will provide an overview of this research (mostly done by people other than me) and propose that Typed Lisp deserves a place in the world of cutting-edge programming languages.

Biography

Drew McDermott is Professor of Computer Science at Yale University. He was educated at MIT, where he received a Ph.D. in 1976. His research is in planning and knowledge representation, with side excursions into philosophy. He has been one the prime movers of the International Planning Competition, and the language it spawned, the Planning Domain Definition Language (PDDL), that is now the accepted standard for expression of planning domains and problems. His 1996 paper on the heuristic-search approach to planning was just named co-winner of the ICAPS Classic Paper Award. He is a Fellow of the American Association for Artificial Intelligence.