Unbreakable and breakable quantum censorship

Abstract

A protocol for regulating the distribution of quantum information between multiple parties is put forward. In order to prohibit the unrestricted distribution of quantum-resource states in a public quantum network, agents can apply a resource-destroying map to each sender's channel. Since resource-destroying maps only exist for affine quantum resource theories, censorship of a nonaffine resource theory is established on an operationally motivated subspace of free states. This is achieved by using what we name a resource-censoring map. The protocol is applied to censoring coherence, reference frames, and entanglement. Because of the local nature of the censorship protocol, it is, in principle, possible for collaborating parties to bypass censorship. Thus, we additionally derive necessary and sufficient conditions under which the censorship protocol is unbreakable.