Hundreds of millions of people rely on a virtual private network, or VPN, app to guard their data, but there’s cause for concern about breaches of the defenses set up to protect users’ data on the app. Benjamin Mixon-Baca, a computer science doctoral student in the School of Computing and Augmented Intelligence, part of the Ira A. Fulton Schools of Engineering  has helped to expose ways information on the app can be revealed and shared. His paper, coauthored by Jedidiah Crandall, a Fulton Schools associate professor of computer science and engineering, and Jeffrey Knockel of Citizen Lab, details those security failures. Mixon-Baca applied skills he learned in school’s doctoral program to expose the threat to VPNs, Crandall says. An earlier version was posted on Full Circle, the Fulton Schools’ website news page.