$\mathbf{VDF} \subsetneq \mathbf{PSPACE}$

TL;DR

This paper explores the computational complexity of verifiable delay functions (VDFs), establishing that all VDFs are within PSPACE but not all PSPACE problems have VDFs, highlighting their limitations and scope.

Contribution

It proves that VDFs are contained within PSPACE and that PSPACE encompasses problems that do not admit VDFs, clarifying their computational boundaries.

Findings

VDFs are provable in PSPACE.

Not all PSPACE problems admit VDFs.

VDFs are a strict subset of PSPACE.

Abstract

Verifiable delay functions (VDF) are functions that take a specified number of sequential steps to be evaluated but can be verified efficiently. In this paper, we show that every VDF is provable in PSPACE but every language in PSPACE does not admit to a VDF.