A framework for quantum homomorphic encryption with experimental demonstration

TL;DR

This paper introduces a flexible framework for quantum homomorphic encryption that combines classical and quantum methods, and demonstrates key components experimentally, advancing secure quantum computation.

Contribution

It proposes a new framework for interactive quantum homomorphic encryption based on the universal circuit approach, with experimental validation of key steps.

Findings

Framework integrates classical and quantum techniques for QHE.

Experimental demonstration of key protocol components.

Low quantum capability requirements for participating parties.

Abstract

Quantum homomorphic encryption (QHE) is an encryption method that allows quantum computation to be performed on one party's private data with the program provided by another party, without revealing much information about the data nor the program to the opposite party. We propose a framework for (interactive) QHE based on the universal circuit approach. It contains a subprocedure of calculating a classical linear polynomial, which can be implemented with quantum or classical methods; apart from the subprocedure, the framework has low requirement on the quantum capabilities of the party who provides the circuit. We illustrate the subprocedure using a quite simple classical protocol with some privacy tradeoff. For a special case of such protocol, we obtain a scheme similar to blind quantum computation but with the output on a different party. Another way of implementing the subprocedure is to use a recently studied quantum check-based protocol, which has low requirement on the quantum capabilities of both parties. The subprocedure could also be implemented with a classical additive homomorphic encryption scheme. We demonstrate some key steps of the outer part of the framework in a quantum optics experiment.