TY - GEN

T1 - Public-Key Encryption with Quantum Keys

AU - Barooti, Khashayar

AU - Grilo, Alex B.

AU - Huguenin-Dumittan, Loïs

AU - Malavolta, Giulio

AU - Sattath, Or

AU - Vu, Quoc Huy

AU - Walter, Michael

N1 - Publisher Copyright:
© International Association for Cryptologic Research 2023.

PY - 2023/1/1

Y1 - 2023/1/1

N2 - 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 these worlds can change when quantum information is taken into account. Recent work has shown that quantum variants of oblivious transfer and multi-party computation, both primitives that are classically in Cryptomania, can be constructed from one-way functions, placing them in the realm of quantum MiniCrypt (the so-called MiniQCrypt). This naturally raises the following question: Is it possible to construct a quantum variant of public-key encryption, which is at the heart of Cryptomania, from one-way functions or potentially weaker assumptions? In this work, we initiate the formal study of the notion of quantum public-key encryption (qPKE), i.e., public-key encryption where keys are allowed to be quantum states. We propose new definitions of security and several constructions of qPKE based on the existence of one-way functions (OWF), or even weaker assumptions, such as pseudorandom function-like states (PRFS) and pseudorandom function-like states with proof of destruction (PRFSPD). Finally, to give a tight characterization of this primitive, we show that computational assumptions are necessary to build quantum public-key encryption. That is, we give a self-contained proof that no quantum public-key encryption scheme can provide information-theoretic security.

AB - 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 these worlds can change when quantum information is taken into account. Recent work has shown that quantum variants of oblivious transfer and multi-party computation, both primitives that are classically in Cryptomania, can be constructed from one-way functions, placing them in the realm of quantum MiniCrypt (the so-called MiniQCrypt). This naturally raises the following question: Is it possible to construct a quantum variant of public-key encryption, which is at the heart of Cryptomania, from one-way functions or potentially weaker assumptions? In this work, we initiate the formal study of the notion of quantum public-key encryption (qPKE), i.e., public-key encryption where keys are allowed to be quantum states. We propose new definitions of security and several constructions of qPKE based on the existence of one-way functions (OWF), or even weaker assumptions, such as pseudorandom function-like states (PRFS) and pseudorandom function-like states with proof of destruction (PRFSPD). Finally, to give a tight characterization of this primitive, we show that computational assumptions are necessary to build quantum public-key encryption. That is, we give a self-contained proof that no quantum public-key encryption scheme can provide information-theoretic security.

UR - http://www.scopus.com/inward/record.url?scp=85178662239&partnerID=8YFLogxK

U2 - 10.1007/978-3-031-48624-1_8

DO - 10.1007/978-3-031-48624-1_8

M3 - Conference contribution

AN - SCOPUS:85178662239

SN - 9783031486234

T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

SP - 198

EP - 227

BT - Theory of Cryptography - 21st International Conference, TCC 2023, Proceedings

A2 - Rothblum, Guy

A2 - Wee, Hoeteck

PB - Springer Science and Business Media Deutschland GmbH

T2 - 21st International conference on Theory of Cryptography Conference, TCC 2023

Y2 - 29 November 2023 through 2 December 2023

ER -