Anonymous transmission in a noisy quantum network using the W state

We consider the task of anonymously transmitting a quantum message in a network. In this task, we are concerned with hiding the identities of the sender and receiver of the message from other nodes of the network. We present a protocol that accomplishes this task using the W state. We analyze its performance in a quantum network where common forms of noise are present, and then compare the performance of our protocol with some of the existing protocols developed for the task of anonymous transmission. We show that, in many regimes, our protocol tolerates more noise and achieves higher fidelities of the transmitted quantum message than the other ones. Furthermore, we demonstrate that our protocol tolerates one non-responsive node, as opposed to other considered protocols. Finally, we prove the security of our protocol in a semi-active adversary scenario, i.e. when the adversary is active and the source of a quantum state is trusted.