Alumni profile: Raquel Hill, Ph.D. '02

Had her advisor not required her to write an additional chapter for her dissertation, Raquel Hill’s career might have gone in a completely different direction. Hill was getting ready to receive her Ph.D. in computer science at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) in May 2002 when H.T. Kung, William H. Gates Professor of Computer Science and Electrical Engineering, told her to do a security analysis of the protocol she’d developed for transmitting audio and video data with quality guarantees.

“He asked what I thought of that, and I said, ‘I am the student, and you are my advisor. If you think I should write another chapter, that is what I’ll do,’” Hill said. “I didn’t know at the time that cybersecurity would be as big as it is, but that’s how I got involved with it. So I’m very thankful for having to stay a few more months at Harvard to do my security analysis, because that’s what positioned me to explore securing systems, trustworthiness of systems and data privacy.”

Since getting her degree from SEAS, Hill has spent more than two decades in academia, where the bulk of her research has been about data security and privacy. She pursued postdoctoral positions at Georgia Tech, where she’d earned bachelor’s and master’s degrees in computer science, as well as the University of Illinois at Champaign-Urbana, and from there spent 14 years at the Indiana University, where she was an Assistant and later Associate Professor of computer science, as well as Director of Cybersecurity Academic Programs at Indiana’s School of Informatics, Computing, and Engineering. Since 2019, Hill has served as Chair of Computer and Information Sciences and Professor at Spelman College, an HBCU (Historically Black Colleges and Universities) in her home state of Georgia.

“I think I’ve always been an educator and didn’t know it,” Hill said. “When I finished my Ph.D., I reached out to Spelman then and said I was interested. I didn’t get a response, so I said to myself that one day I’d like to be the chair of the computer science department. I was thinking about Spelman even as a teenager because of its history of educating Black women.”

At Spelman, Hill is helping make sure the next generation of computer science researchers will understand the security implications of their work. It’s a topic she explored at Indiana, when her team showed how even anonymous survey data could be used to identify someone.

“That’s when I really began to understand that this isn’t just a security problem, because it was more about how much one could learn from data that was released,” she said. “It really got me thinking about issues of privacy. Now, it’s an even bigger challenge with large language models. All the data that’s being pulled, people are using them without careful consideration of what they’re sharing while they’re using, and whether they own what’s generated based on that data. It’s taken issues of privacy and ownership of information to a whole other level.”

Along with instilling a focus on security and privacy, Hill is also helping diversify a field with very little Black representation. Just 1.2 percent of computer science doctorates from U.S. institutions went to Black students in 2022, and Hill was the first Black person to receive a Ph.D. in computer science from Harvard. In 2019, she hooded the first Black woman to receive a Ph.D. from Purdue University.

“It’s important for students to feel as if they have a safe and supportive space to learn. I feel safe when I can find comfort in the familiar. I came from Georgia Tech, and before that a high school that was probably 95 percent Black. Harvard was far less diverse and even more isolating than Georgia Tech,” she said. “But with every challenge, there’s an opportunity, and the feelings of isolation that I felt at Harvard provided an opportunity to broaden my perspective on education and how I viewed and approached the solutions to problems. To address my feelings of isolation, I sought community in the other disciplines because throughout my time at Harvard, I was often the only Black graduate student within the School of Engineering and Applied Sciences. By finding friends in the social sciences, medical sciences and other graduate school programs on campus, and with my colleagues at MIT and engaging in their research discussions, I developed an appreciation for their diverse perspectives. These diverse perspectives shape the way I approach my research even today. Harvard provided an opportunity for me to expand my interests and develop an inter-disciplinary approach to research.”

For Hill, diversity goes beyond race or demographics. Homogeneity of any sort, whether it’s in a community or a company’s technology, can lead to vulnerability. For example, facial recognition software has been shown to be more accurate for White faces than Black ones, likely due to a lack of diversity in the dataset of faces used to train the software.

The only way to combat such vulnerabilities is to have broader representation.

“If you have a homogeneous environment where everyone’s running the same operating system, every machine has the same vulnerability, and everybody can be exploited,” she said. “We need something that’s going to be robust and resilient, and in order to do that, we need heterogeneity. Even on a biological level, if all our cells were the same, anything that attacks us could just wipe us out. You need diverse backgrounds and perspectives to design and build robust solutions to today’s problems.”

Whether her undergraduates continue on to graduate education or enter the workforce, Hill hopes her students will be able to help bring that robustness to the computer science space.

“I want to prepare them to pursue graduate degrees, or whatever they want to pursue,” Hill said. “You don’t pursue a Ph.D. just to have those three letters behind your name and two letters in front. You must have a passion for learning, conducting research and solving problems. When it comes to training students, the first thing I always do is have high expectations for their performance. When others view you as not capable of excellence, that shapes everything. At a baseline, I expect all my students to perform excellently, to give me their personal best.”