Qubit-based unclonable encryption with key recycling (pp901-930)
          Daan Leermakers and Boris Skoric
          doi: https://doi.org/10.26421/QIC21.11-12-1
Abstracts: We re-visit Unclonable Encryption as introduced by Gottesman in~2003 \cite{uncl}. We look at the combination of Unclonable Encryption and Key Recycling, while aiming  for low communication complexity and high rate. We introduce a qubit-based prepare-and-measure Unclonable Encryption scheme with re-usable keys. Our scheme consists of a single transmission by Alice and a single classical feedback from Bob. The transmission from Alice to Bob consists entirely of qubits. The rate, defined as the message length divided by the number of qubits, is higher than what can be achieved using Gottesman's scheme~\cite{uncl}. We provide a security proof based on the diamond norm distance, taking noise into account.
Key words: unclonable encryption; Quantum Key Recycling; quantum cryptogtraphy