Encrypted Qubits can be Cloned

TL;DR

This paper introduces a method for encrypted cloning of unknown quantum states, allowing creation and decryption of multiple encrypted copies via unitary transformations, which could enable scalable encrypted quantum storage.

Contribution

It demonstrates that encrypted cloning of quantum states is feasible, providing a new paradigm for quantum redundancy and scalability within the constraints of the no-cloning theorem.

Findings

Encrypted clones can be created and decrypted using unitary transformations.

Only one decryption per encrypted clone is possible, respecting the no-cloning theorem.

Potential application in encrypted quantum multi-cloud storage.

Abstract

We show that encrypted cloning of unknown quantum states is possible. Any number of encrypted clones of a qubit can be created through a unitary transformation, and each of the encrypted clones can be decrypted through a unitary transformation. The decryption of an encrypted clone consumes the decryption key, i.e., only one decryption is possible, in agreement with the no-cloning theorem. Encrypted cloning represents a new paradigm that provides a form of redundancy, parallelism or scalability where direct duplication is forbidden by the no-cloning theorem. For example, a possible application of encrypted cloning is to enable encrypted quantum multi-cloud storage.