English

Quantum-Computable One-Way Functions without One-Way Functions

Quantum Physics 2025-09-18 v1 Computational Complexity Cryptography and Security

Abstract

We construct a classical oracle relative to which P=NP\mathsf{P} = \mathsf{NP} but quantum-computable quantum-secure trapdoor one-way functions exist. This is a substantial strengthening of the result of Kretschmer, Qian, Sinha, and Tal (STOC 2023), which only achieved single-copy pseudorandom quantum states relative to an oracle that collapses NP\mathsf{NP} to P\mathsf{P}. For example, our result implies multi-copy pseudorandom states and pseudorandom unitaries, but also classical-communication public-key encryption, signatures, and oblivious transfer schemes relative to an oracle on which P=NP\mathsf{P}=\mathsf{NP}. Hence, in our new relativized world, classical computers live in "Algorithmica" whereas quantum computers live in "Cryptomania," using the language of Impagliazzo's worlds. Our proof relies on a new distributional block-insensitivity lemma for AC0\mathsf{AC^0} circuits, wherein a single block is resampled from an arbitrary distribution.

Keywords

Cite

@article{arxiv.2411.02554,
  title  = {Quantum-Computable One-Way Functions without One-Way Functions},
  author = {William Kretschmer and Luowen Qian and Avishay Tal},
  journal= {arXiv preprint arXiv:2411.02554},
  year   = {2025}
}

Comments

33 pages, 1 figure

R2 v1 2026-06-28T19:48:05.500Z