Paper 2026/1210
Uncloneable Cryptography in Linear Quantum Memory
Abstract
Quantum cryptography is a rapidly developing area which leverages quantum information to accomplish classically impossible tasks. In many of these protocols, quantum states are used as long-term cryptographic keys, relying on the quantum no-cloning theorem to ensure that the keys cannot be copied by an adversary. Unfortunately, quantum state tend to decohere, and hence, persistent quantum memory is and will remain one of the most valuable and challenging resources for quantum computers. As such, it will be important to minimize the extent to which our protocols use persistent quantum memory. In this work, we consider the case of one-shot signatures (OSS), and more general quantum signing tokens, important uncloneable primitives where quantum signing keys allow for signing a single message but not two. Very recently, the first OSS scheme was constructed unconditionally in a classical oracle model as well as in the standard model under cryptographic assumptions (Shmueli and Zhandry, CRYPTO 2025). We observe that the quantum memory required for these protocols is a large polynomial (in the security parameter). The main contribution of this work is to significantly decrease the quantum secret key size, in some cases achieving the asymptotically optimal size. One of our schemes guarantees perfect correctness and the other one admits a parallel signing algorithm for long messages. We also achieve strong signature incompressibility, which implies a public-key quantum fire scheme (Çakan, Goyal and Shmueli, QCrypt 2025) with perfect correctness. During the course of this work, we develop novel techniques for proving the security of cryptosystems using coset states, one of the main tools used in uncloneable cryptography.
Note: This article is the full version of a paper accepted at CRYPTO 2026; it is also a merger of the following two works, and subsumes both the works: [HV25] (https://eprint.iacr.org/2025/1906) and [SZ25] (https://eprint.iacr.org/2025/2056).
Metadata
- Available format(s)
-
PDF
- Category
- Foundations
- Publication info
- A major revision of an IACR publication in CRYPTO 2026
- Keywords
- Quantum CryptographyOne-Shot SignaturesUnclonable Cryptography
- Contact author(s)
-
ahuang @ mit edu
omri shmueli1 @ gmail com
vinodv @ csail mit edu
mzhandry @ stanford edu - History
- 2026-06-10: approved
- 2026-06-08: received
- See all versions
- Short URL
- https://ia.cr/2026/1210
- License
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CC BY
BibTeX
@misc{cryptoeprint:2026/1210,
author = {Andrew Huang and Omri Shmueli and Vinod Vaikuntanathan and Mark Zhandry},
title = {Uncloneable Cryptography in Linear Quantum Memory},
howpublished = {Cryptology {ePrint} Archive, Paper 2026/1210},
year = {2026},
url = {https://eprint.iacr.org/2026/1210}
}
