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Related papers: Quantum Cryptography and Meta-Complexity

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Although one-way functions are well-established as the minimal primitive for classical cryptography, a minimal primitive for quantum cryptography is still unclear. Universal extrapolation, first considered by Impagliazzo and Levin (1990),…

Quantum Physics · Physics 2025-04-15 Luowen Qian , Justin Raizes , Mark Zhandry

While one-way functions (OWFs) serve as the minimal assumption for computational cryptography in the classical setting, in quantum cryptography, we have even weaker cryptographic assumptions such as pseudo-random states, and EFI pairs,…

Quantum Physics · Physics 2025-04-22 Alex B. Grilo , Álvaro Yángüez

In the framework of Impagliazzo's five worlds, a distinction is often made between two worlds, one where public-key encryption exists (Cryptomania), and one in which only one-way functions exist (MiniCrypt). However, the boundaries between…

Post-quantum cryptography currently rests on a small number of hardness assumptions, posing significant risks should any one of them be compromised. This vulnerability motivates the search for new and cryptographically versatile assumptions…

Quantum Physics · Physics 2026-03-20 Jonathan Z. Lu , Alexander Poremba , Yihui Quek , Akshar Ramkumar

Quantum pseudorandomness has found applications in many areas of quantum information, ranging from entanglement theory, to models of scrambling phenomena in chaotic quantum systems, and, more recently, in the foundations of quantum…

Quantum Physics · Physics 2025-07-23 John Bostanci , Jonas Haferkamp , Dominik Hangleiter , Alexander Poremba

Unpredictable functions (UPFs) play essential roles in classical cryptography, including message authentication codes (MACs) and digital signatures. In this paper, we introduce a quantum analog of UPFs, which we call unpredictable state…

Quantum Physics · Physics 2025-03-27 Tomoyuki Morimae , Shogo Yamada , Takashi Yamakawa

One-way functions (OWFs) form the foundation of modern cryptography, yet their unconditional existence remains a major open question. In this work, we study this question by exploring its relation to lossy reductions, i.e., reductions $R$…

Cryptography and Security · Computer Science 2025-07-01 Pouria Fallahpour , Alex B. Grilo , Garazi Muguruza , Mahshid Riahinia

In quantum cryptography, there could be a new world, Microcrypt, where cryptography is possible but one-way functions (OWFs) do not exist. Although many fundamental primitives and useful applications have been found in Microcrypt, they lack…

Quantum Physics · Physics 2024-10-08 Tomoyuki Morimae , Keita Xagawa

We prove that it is impossible to construct perfect-complete quantum public-key encryption (QPKE) with classical keys from quantumly secure one-way functions (OWFs) in a black-box manner, resolving a long-standing open question in quantum…

Quantum Physics · Physics 2025-04-09 Longcheng Li , Qian Li , Xingjian Li , Qipeng Liu

We construct quantum public-key encryption from one-way functions. In our construction, public keys are quantum, but ciphertexts are classical. Quantum public-key encryption from one-way functions (or weaker primitives such as pseudorandom…

Quantum Physics · Physics 2024-05-27 Fuyuki Kitagawa , Tomoyuki Morimae , Ryo Nishimaki , Takashi Yamakawa

A fundamental pursuit in complexity theory concerns reducing worst-case problems to average-case problems. There exist complexity classes such as PSPACE that admit worst-case to average-case reductions. However, for many other classes such…

Quantum Physics · Physics 2020-09-02 Nai-Hui Chia , Sean Hallgren , Fang Song

We prove that the equivalence of two fundamental problems in the theory of computing. For every polynomial $t(n)\geq (1+\varepsilon)n, \varepsilon>0$, the following are equivalent: - One-way functions exists (which in turn is equivalent to…

Computational Complexity · Computer Science 2020-09-25 Yanyi Liu , Rafael Pass

We show that concrete hardness assumptions about learning or cloning the output state of a random quantum circuit can be used as the foundation for secure quantum cryptography. In particular, under these assumptions we construct secure…

Quantum Physics · Physics 2025-04-23 Bill Fefferman , Soumik Ghosh , Makrand Sinha , Henry Yuen

We investigate quantum analogues of collision resistance and obtain separations between quantum ``one-way'' and ``collision-resistant'' primitives. 1. Our first result studies one-wayness versus collision-resistance defined over quantum…

We show the following hold, unconditionally unless otherwise stated, relative to a random oracle: - There are NP search problems solvable by quantum polynomial-time machines but not classical probabilistic polynomial-time machines. - There…

Quantum Physics · Physics 2024-11-12 Takashi Yamakawa , Mark Zhandry

One-way functions are a very important notion in the field of classical cryptography. Most examples of such functions, including factoring, discrete log or the RSA function, can be, however, inverted with the help of a quantum computer. In…

Quantum Physics · Physics 2007-05-23 Elham Kashefi , Iordanis Kerenidis

The seminal work by Impagliazzo and Rudich (STOC'89) demonstrated the impossibility of constructing classical public key encryption (PKE) from one-way functions (OWF) in a black-box manner. However, the question remains: can quantum PKE…

Quantum Physics · Physics 2024-05-31 Longcheng Li , Qian Li , Xingjian Li , Qipeng Liu

In recent years, achieving verifiable quantum advantage on a NISQ device has emerged as an important open problem in quantum information. The sampling-based quantum advantages are not known to have efficient verification methods. This paper…

Quantum Physics · Physics 2025-10-29 Nai-Hui Chia , Honghao Fu , Fang Song , Penghui Yao

Quantum cryptographic definitions are often sensitive to the number of copies of the cryptographic states revealed to an adversary. Making definitional changes to the number of copies accessible to an adversary can drastically affect…

Quantum Physics · Physics 2026-03-10 Prabhanjan Ananth , Eli Goldin

We introduce the pseudorandom quantum authentication scheme (PQAS), an efficient method for encrypting quantum states that relies solely on the existence of pseudorandom unitaries (PRUs). The scheme guarantees that for any eavesdropper with…

Quantum Physics · Physics 2025-01-03 Tobias Haug , Nikhil Bansal , Wai-Keong Mok , Dax Enshan Koh , Kishor Bharti