A Note on Copy-Protection from Random Oracles

TL;DR

This paper explores the limits of quantum copy-protection in the random oracle model, establishing impossibility results under certain cryptographic assumptions and highlighting fundamental challenges in quantum software security.

Contribution

It provides the first impossibility results for quantum copy-protection in the random oracle model for unlearnable functions, assuming quantum cryptographic hardness.

Findings

Impossibility of approximately correct copy-protection in the plain model.

Impossibility of certain copy-protection schemes in the random oracle model.

Results depend on quantum fully homomorphic encryption and hardness assumptions.

Abstract

Quantum copy-protection, introduced by Aaronson (CCC'09), uses the no-cloning principle of quantum mechanics to protect software from being illegally distributed. Constructing copy-protection has been an important problem in quantum cryptography. Since copy-protection is shown to be impossible to achieve in the plain model, we investigate the question of constructing copy-protection for arbitrary classes of unlearnable functions in the random oracle model. We present an impossibility result that rules out a class of copy-protection schemes in the random oracle model assuming the existence of quantum fully homomorphic encryption and quantum hardness of learning with errors. En route, we prove the impossibility of approximately correct copy-protection in the plain model.