Quantum Alice and silent Bob: Qubit-based Quantum Key Recycling with almost no classical communication

We answer an open question about Quantum Key Recycling (QKR): Is it possible to put the message entirely in qubits without increasing number of compared existing QKR schemes? show that this is indeed possible. introduce a prepare-and-measure protocol where communication from Alice Bob consists qubits. As usual, responds with authenticated one-bit accept/reject classical message. Compared Distribution (QKD), has reduced round complexity. previous qubit-based protocols, our scheme far less communication. provide security proof universal composability framework and find rate asymptotically same as for QKD one-way postprocessing.