Distinguished Lecture Series - A Cryptic Letter to Thomas Jefferson


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.

Adversarial Machine Learning in Relational Domains


As classifiers are deployed to detect malicious behavior ranging from spam to terrorism, adversaries modify their behaviors to avoid detection. This makes the very behavior the classifier is trying to detect a function of the classifier itself. Learners that account for concept drift are not sufficient since they do not allow the change in concept to depend on the classifier. As a result, humans must adapt the classifier with each new attack. Ideally, we would like to see classifiers that are resistant to attack and that respond to successful attacks automatically.

Resolving and Exploiting the k-CFA Paradox


Low-level program analysis is a fundamental problem, taking the shape of "flow analysis" in functional languages and "points-to" analysis in imperative and object-oriented languages. Despite the similarities, the vocabulary and results in the two communities remain largely distinct, with limited cross-understanding. One of the few links is Shivers's k-CFA work, which has advanced the concept of "context-sensitive analysis" and is widely known in both communities.


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