2026-04-10 –, Glatt (Y22-F-68/70)
Verifiable Random Functions (VRFs) are a critical building block for many consensus protocols in PoS blockchains.
However, such applications require a strong security property called "unbiasability" that is not covered by the traditional security properties correctness, pseudorandomness and uniqueness.
In this talk I will showcase a surprisingly simple Hash-then-VRF construction that adds provable unbiasability (in the standard model) to any VRF at negligible cost.
Our construction is superior compared the folklore VUF-then-Hash construction in both security and potentially efficiency.
While our construction is extremely simple, the analysis requires a newly developed non-black-box technique that leverages a special property that all known VRFs have.
Nicholas is a researcher working with [[alloc] init]. He recently obtained his PhD from ETH Zürich in the group of Dennis Hofheinz. His research spans from fundamental complexity theory all the way to applied cryptography including Kolmogorov complexity, verifiable random functions, secure multi-party computation, key transparency and more.