Séminaire Algorithmique : « Post-Quantum Public-Key Pseudorandom Correlation Functions for Oblivious Transfer », Mahshid Riahinia (ENS Paris et IRIF, Univ. Paris Cité)

Public-Key Pseudorandom Correlation Functions (PK-PCF) are functions that generate pseudorandom correlated strings. These correlations can then be used to speed up secure computation protocols. Recent works have made significant progress building PK-PCFs using group-based assumptions, however, these assumptions do not hold up against quantum attackers. Much less is known about PK-PCFs in the post-quantum regime. In this talk, I will introduce an efficient lattice-based PK-PCF for oblivious transfer (OT) correlations. At the heart of our result lie several technical contributions that might be of independent interest. In particular, we introduce the first efficient lattice-based constrained pseudorandom functions for low-degree polynomials, from a new but natural “secret-power” variant of ring learning with errors (ring-LWE) assumption.