Quantum encryption with certified deletion

TL;DR

This paper demonstrates that quantum encryption enables certified deletion of data, allowing a recipient to prove they have relinquished the ability to recover the plaintext, unlike classical encryption.

Contribution

It introduces a quantum encryption scheme that allows certified deletion with practical implementation and noise robustness, a novel feature not possible with classical methods.

Findings

Quantum encryption enables certified deletion of data.

The scheme is feasible with current quantum technology.

The protocol is robust against noise and suitable for finite-key regimes.

Abstract

Given a ciphertext, is it possible to prove the deletion of the underlying plaintext? Since classical ciphertexts can be copied, clearly such a feat is impossible using classical information alone. In stark contrast to this, we show that quantum encodings enable certified deletion. More precisely, we show that it is possible to encrypt classical data into a quantum ciphertext such that the recipient of the ciphertext can produce a classical string which proves to the originator that the recipient has relinquished any chance of recovering the plaintext should the decryption key be revealed. Our scheme is feasible with current quantum technology: the honest parties only require quantum devices for single-qubit preparation and measurements; the scheme is also robust against noise in these devices. Furthermore, we provide an analysis that is suitable in the finite-key regime.