Skip to main content

New Faculty 2012: Privacy in an Online World

Ashwin Machanavajjhala develops algorithms to keep individual's personal information private

Ashwin Machanavajjhala brings a strong record of work on data privacy in the private sector to the Duke computer science faculty.  Photo by Les Todd/Duke University Photography
Ashwin Machanavajjhala brings a strong record of work on data privacy in the private sector to the Duke computer science faculty. Photo by Les Todd/Duke University Photography

In 2006, AOL, or America Online, decided to make its users' searches publicly available on the Internet for research. Although AOL made user information anonymous, reporters from the New York Times used solely the search to identify one of the users. Ashwin Machanavajjhala's work tries to prevent those kinds of breaches of individual's private information.

"Our digital footprint is collected and analyzed by entities such as web companies, in most cases, without our knowledge. This footprint reveals sensitive information about us such as where we live, what we eat, who we hang out with, and even our political affiliations or sexual orientation," Machanavajjhala said.

Read More

He joined Duke in the summer of 2012 as an assistant professor in the computer science department. Here, he hopes to develop a privacy-aware practical tool kit that will allow researchers to analyze individual data from social networks and genome datasets, among other sources, without revealing sensitive information about people.

Prior to coming to Duke, Machanavajjhala was a senior research scientist in the Knowledge Management group at Yahoo!. There, he developed mathematical tools to analyze large amounts of data, manage it efficiently and make sure that the information that should remain private did. He has also developed algorithms for the U.S. Census to protect individual privacy. 

"Privacy and security of data has broad societal implications," said Carlo Tomasi, the chair of Duke's computer science department. "Ashwin's previous experience at Yahoo! Research gives him a clear sense of what is relevant and important."  

"Many of our faculty members are interested in privacy and security of information," Tomasi said. "Ashwin will strengthen these colleagues' efforts and tie the privacy aspects of their research threads together, multiplying the impact of our department's work in this area." 

Machanavajjhala was first introduced to computers in the fifth grade. Since then, he maintained a keen interest in the field, later graduating with a Bachelors of Technology degree in computer science from the Indian Institute of Technology in Madras. He then came to the U.S. to start graduate school at Cornell.

The concept of data privacy was not well established when he started graduate school, he said, explaining that he was able to develop one of the first mathematical definitions of data privacy as part of his Ph.D. thesis. Since then, he has tackled privacy issues in social networks, advertising and web search and now wants to extend his work to genome analysis and data from mobile technology.

He also wants to expand his work with students. While at Yahoo!, he had the opportunity to work with student interns, but he really wanted to "mold and shape" the next generation of computer scientists and thought-leaders, which is part of the reason he returned to academia. In the fall 2012 semester, he is teaching Privacy in a Mobile-Social World, a class about the terabytes of personal data collected, analyzed and shared each day through mobile and social applications.

Machanavajjhala thinks that an expertise in privacy issues and technologies is a vital skill for students planning to work in any industry -- web, medical or otherwise. Releasing private information to third parties, such as advertisers or researchers, "has tremendous scientific and commercial value," but it can also lead to leaks in sensitive information, he said. He said he hopes his lectures and class discussions encourage some of his students to become leaders in the data privacy arena.