A New World in the Depths of Microcrypt: Separating OWSGs and Quantum Money from QEFID
Amit Behera, Giulio Malavolta, Tomoyuki Morimae, Tamer Mour, Takashi Yamakawa

TL;DR
This paper demonstrates, through a quantum oracle, that EFI pairs can exist without OWSGs, providing a separation that clarifies the minimal assumptions needed for certain quantum cryptographic primitives.
Contribution
It establishes a quantum oracle separation between EFI pairs and OWSGs, showing that EFI pairs do not necessarily imply OWSGs, and clarifies the landscape of minimal assumptions in quantum cryptography.
Findings
EFI pairs can exist without OWSGs in a quantum oracle
Separates QEFID and one-way puzzles from OWSGs using oracle techniques
Establishes a black-box separation between quantum money schemes and QEFID
Abstract
While in classical cryptography, one-way functions (OWFs) are widely regarded as the "minimal assumption," the situation in quantum cryptography is less clear. Recent works have put forward two concurrent candidates for the minimal assumption in quantum cryptography: One-way state generators (OWSGs), postulating the existence of a hard search problem with an efficient verification algorithm, and EFI pairs, postulating the existence of a hard distinguishing problem. Two recent papers [Khurana and Tomer STOC'24; Batra and Jain FOCS'24] showed that OWSGs imply EFI pairs, but the reverse direction remained open. In this work, we give strong evidence that the opposite direction does not hold: We show that there is a quantum unitary oracle relative to which EFI pairs exist, but OWSGs do not. In fact, we show a slightly stronger statement that holds also for EFI pairs that output classical…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
Taxonomy
TopicsBenford’s Law and Fraud Detection · Blockchain Technology Applications and Security
