Verifiable Privacy‐Preserving Quantum Protocol for Blind Millionaire Problem and Its Application in Privacy Computing

Abstract Blind millionaire (BM) problem aims to privately compare the summation result of secrets of participants from one group with that from another group without compromising their respective secrets. Although several quantum BM protocols are presented, it is pointed out that the correctness of these quantum BM protocols is not ensured. Then, a mechanism of permuting the embedding orders of all the participants in an anonymous manner is provided. Furthermore, a new quantum BM protocol based on the proposed anonymous embedding mechanism is proposed. It is shown that this protocol possesses the properties of privacy, self‐comparing, verifiability and fairness at the same time, and satisfies the security requirement of a quantum BM protocol in theory. In addition, the use of single‐particle states and simple shift operations makes the proposed protocol feasible with current technology. To demonstrate the scalability of the designed protocol, its applications in several privacy computing problems in real‐world scenarios such as joint bidding and preference survey are illustrated.