Post-Quantum Verifiable Oblivious Pseudorandom Functions

Abstract

This work presents the construction of a post-quantum verifiable oblivious pseudorandom function (VOPRF) with a focus on efficiency and practicality. Leveraging lattice-based cryptographic primitives, particularly the Learning With Errors (LWE) problem, our VOPRF construction aims to address the limitations of existing approaches by reducing proof sizes. The key component in our work is the integration of an efficient zero-knowledge proof of knowledge (ZKPoK) protocol. This ZKPoK is notably more efficient than the proof systems used in prior VOPRF constructions, ensuring the verifiability of PRF outputs while providing smaller proof sizes. Our construction relies on the hardness of the ring-LWE and short integer solution (SIS) problems, and we demonstrate its security in the random oracle model. Overall, our VOPRF construction represents a step towards the development of more practical post-quantum secure cryptographic protocols, highlighting the potential for further improvements in efficiency and real-world applicability.