Search engines and recommendation systems are central to how we interact in the Internet, but they pose significant privacy risks. Even when they are assumed secure, information (such as search queries, click behavior, and recommendation interactions) can be used to track, profile, and infer sensitive information. Private Information Retrieval (PIR) offers a promising solution, enabling users to query and retrieve information without revealing their interests.
This talk will explore the foundations of PIR, its recent advancements, and its practical applications in search engines and recommendation systems. We will discuss how PIR can be integrated into large-scale systems while balancing efficiency and usability. We will also outline key challenges (such as deployment barriers, economic feasibility, and open research problems) that need to be addressed for PIR to become a widely adopted privacy-enhancing technology.
Speaker's Biography: Sofía Celi is a Senior Cryptography Researcher at Brave, specializing in privacy-enhancing technologies, post-quantum cryptography, and secure communication systems. She is a member of the Advisory Council at the Open Technology Fund (OTF) and holds leadership roles within the IETF, IRTF, and W3C. Sofía has also provided expert consultations for the United Nations and human rights organizations, focusing on the intersection of emerging technologies and digital rights.
As a co-founder of Criptolatinos and Women in Cryptography, Sofía is committed to fostering diversity in cryptography and security. She is actively engaged in the academic community, serving as a member of the Latincrypt Steering Committee, Publicity Co-Chair of the PETS Symposium, IACR ePrint Co-Editor, and IEEE Security & Privacy Ethics Co-Chair.
Sofía has received the Distinguished Paper Award at IEEE S&P, was a runner-up for the Best Paper Award at ESORICS and for the Pwnie Award.
Sofía lives with her amazing partner, Jurre van Bergen, and has two beloved dogs.