Unconditionally secure quantum commitments with preprocessing

Abstract

We demonstrate how to build computationally secure commitment schemes with the aid of quantum auxiliary inputs without unproven complexity assumptions. Furthermore, the quantum auxiliary input can be either sampled in uniform exponential time or prepared in at most doubly exponential time, without relying on an external trusted third party. Classically, this remains impossible without first proving $\mathsf{P} \neq \mathsf{NP}$.