Mobile devices such as smartphones and wearable health care devices can be valuable sources of information. Location information, pictures, recorded sounds and health information can all be collected and used to study anything from traffic patterns to flu outbreaks. But mobile device users are reluctant to share these personal details unless they can be sure they will be kept private.

Assistant professor Qinghua Li is looking for new ways to guarantee privacy in these situations. He designs novel encryption schemes which allow data collectors to collect the aggregate statistics of a group without knowing the value of any individual user's data. "They allow you, for example, to count the number of users infected with a new flu without knowing if a given user is infected," he explained.

In this scheme, when a user submits data, this data is encrypted. The data collector uses a key to obtain the aggregate statistics from users' encrypted data, but the key can not be used to decrypt each user's original data value. Li uses combinatorics and efficient cryptography to design the methods of encrypting user data and decrypting aggregate statistics.

Li also addresses other issues related to data collection, such as providing privacy-preserving payments to users and making sure that data is accurate and trustworthy by ruling out forgery or malfunctioning devices.

In general, Li addresses security and privacy issues for networking and computing systems, including mobile sensing, healthcare systems, smart grid, and mobile cloud computing. His research integrates cryptography, theory, and system building to develop simple, effective, and practical solutions for challenging security and privacy problems.

"I am very pleased to add Dr. Qinghua Li to our department's faculty," said Susan Gauch, head of the department of computer science and computer engineering. "His research into privacy and security is an important strength to add to our National Science Agency/Department of Homeland Center of Academic Excellence in Information Assurance Research."  

Several factors attracted Li to the University of Arkansas, including the Information Assurance Center and other faculty members working in fields related to data collection and data security and privacy.

Qinghua Li received a doctorate in computer science and engineering at the Pennsylvania State University. He also holds a master's degree in computer science from Tsinghua University in Beijing, China, and bachelor's degrees in computer science and thermal and power engineering from Xi'an Jiaotong University in Xi'an, China. He is joined in Fayetteville by his wife, Yina.