How to Use Quantum Indistinguishability Obfuscation

Andrea Coladangelo; Sam Gunn

Paper 2023/1756

How to Use Quantum Indistinguishability Obfuscation

Andrea Coladangelo

, University of Washington

Sam Gunn

, University of California, Berkeley

Abstract

Quantum copy protection, introduced by Aaronson, enables giving out a quantum program-description that cannot be meaningfully duplicated. Despite over a decade of study, copy protection is only known to be possible for a very limited class of programs. As our first contribution, we show how to achieve "best-possible" copy protection for all programs. We do this by introducing quantum state indistinguishability obfuscation (qsiO), a notion of obfuscation for quantum descriptions of classical programs. We show that applying qsiO to a program immediately achieves best-possible copy protection. Our second contribution is to show that, assuming injective one-way functions exist, qsiO is concrete copy protection for a large family of puncturable programs --- significantly expanding the class of copy-protectable programs. A key tool in our proof is a new variant of unclonable encryption (UE) that we call coupled unclonable encryption (cUE). While constructing UE in the standard model remains an important open problem, we are able to build cUE from one-way functions. If we additionally assume the existence of UE, then we can further expand the class of puncturable programs for which qsiO is copy protection. Finally, we construct qsiO relative to an efficient quantum oracle.

Note: Added citations and minor edits

Metadata

Available format(s): PDF
Category: Foundations
Publication info: Published elsewhere. Minor revision. STOC 2024
DOI: 10.1145/3618260.3649779
Keywords: quantum cryptography copy protection indistinguishability obfuscation unclonable cryptography
Contact author(s): coladan @ cs washington edu
gunn @ berkeley edu
History: 2024-05-03: last of 3 revisions; 2023-11-13: received; See all versions
Short URL: https://ia.cr/2023/1756
License: CC BY

BibTeX

@misc{cryptoeprint:2023/1756,
      author = {Andrea Coladangelo and Sam Gunn},
      title = {How to Use Quantum Indistinguishability Obfuscation},
      howpublished = {Cryptology {ePrint} Archive, Paper 2023/1756},
      year = {2023},
      doi = {10.1145/3618260.3649779},
      url = {https://eprint.iacr.org/2023/1756}
}