CryptoDB
A Fully-Adaptive Threshold Partially-Oblivious PRF
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| Conference: | CRYPTO 2025 |
| Abstract: | Oblivious Pseudorandom Functions (OPRFs) are fundamental cryptographic primitives essential for privacy-enhancing technologies such as private set intersection, oblivious keyword search, and password-based authentication protocols. We present the first fully adaptive, partially oblivious threshold pseudorandom function that supports proactive key refresh and provides composable security under the One-More Gap Diffie-Hellman assumption in the random oracle model. Our construction is secure with respect to a new ideal functionality for OPRFs that addresses three critical shortcomings of previous models--specifically, key refresh and non-verifiability issues that rendered them unrealizable. In addition, we identify a gap in a prior work's proof of partial obliviousness and develop a novel proof technique to salvage their scheme. |
BibTeX
@inproceedings{crypto-2025-35806,
title={A Fully-Adaptive Threshold Partially-Oblivious PRF},
publisher={Springer-Verlag},
author={Ruben Baecker and Paul Gerhart and Daniel Rausch and Dominique Schröder},
year=2025
}