Response to “Comment on ‘Controlled mutual quantum entity authentication with an untrusted third party’”

Abstract

Recently, Wang et al. (Quantum Inf Process, QINP-D-18-00478R1, 2019) commented that a third party can obtain an authentication key from communicating parties by performing an entanglement swapping attack on the controlled mutual quantum entity authentication (CMQEA) protocol. In this response, we apply this attack to the CMQEA protocol and analyze whether this claim is actually valid. From the analysis, we provide a confirmation that this attack can be prevented using existing countermeasures. In addition, we propose an improved protocol that is fundamentally robust to entanglement swapping attack.