CrySP Speaker Series on Privacy

This speaker series is made possible by an anonymous charitable donation in memory of cypherpunks and privacy advocates Len Sassaman, Hugh Daniel, Hal Finney, and Caspar Bowden.

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Private Information Retrieval: Improvements and Limitations

Kevin Yeo, Google and Columbia University

[Download (MP4)] [View on Youtube]

November 23, 2023 2:00pm, in DC 1302 and Zoom


Private information retrieval (PIR) is a very promising cryptographic tool that enables privacy-preserving data querying that has endless implications to real-world applications. Unfortunately, PIR’s high cost remains a hindrance in widespread adoption. In this talk, I cover three PIR topics. First, I will motivate the importance of PIR by walking through a real-world use case at Google deployed today. Next, I will present recent improvements to the concrete efficiency for keyword and batch PIR. Finally, I will discuss recent developments in PIR with preprocessing and explain some limitations and lower bounds to the approach.


Kevin Yeo is a research engineering manager at Google NYC in the Private Computing group as well as a PhD student at Columbia University in the CS theory group. His research interests include cryptography, security, privacy and data structures spanning from understanding theoretical limits to building large-scale systems with strong privacy guarantees. His work has received two USENIX Security distinguished paper awards (2019 & 2023). Kevin's research, including Password Checkup and Private Set Membership, has been deployed to billions of users across Android and Chrome and Kevin's work has also influenced IETF standards for blind signatures.