When we use the internet, most of us don't think twice about entering our credit card numbers and we don't tend to worry that someone might be looking over our shoulder.

Our guest today, Jennifer Rexford, knows better than most how the internet works and what kind of vulnerabilities exist that allow hackers to exploit its weaknesses. She's the Gordon Y.S. Wu professor in engineering, a professor of computer science and the chair of that department here at Princeton. She's won several awards for her research into the way internet traffic is routed. Jen is a 1991 graduate of Princeton with a degree in electrical engineering. She received her Ph. D. from the University of Michigan. She worked at AT&T Labs before joining the Princeton faculty in 2005.