Encryption with Quantum Public Keys

TL;DR

This paper explores constructing quantum public-key encryption schemes from minimal assumptions like one-way functions, proposing three new schemes and revisiting security definitions in the quantum context.

Contribution

It introduces three quantum public-key encryption schemes based on weaker assumptions and revises security definitions for quantum encryption.

Findings

Three quantum encryption schemes from one-way functions and pseudorandom states.

Revised IND-CPA security definition for quantum public-key encryption.

Demonstrated feasibility of quantum encryption under minimal assumptions.

Abstract

It is an important question to find constructions of quantum cryptographic protocols which rely on weaker computational assumptions than classical protocols. Recently, it has been shown that oblivious transfer and multi-party computation can be constructed from one-way functions, whereas this is impossible in the classical setting in a black-box way. In this work, we study the question of building quantum public-key encryption schemes from one-way functions and even weaker assumptions. Firstly, we revisit the definition of IND-CPA security to this setting. Then, we propose three schemes for quantum public-key encryption from one-way functions, pseudorandom function-like states with proof of deletion and pseudorandom function-like states, respectively.