Double-Blind Quantum Identity Authentication Protocol Based on Scalar Product Computation

Quantum identity authentication (QIA) can theoretically realize the unconditional security of identity information. The current QIA protocols generally assume that the pre-agreed keys are not leaked. However, the keys themselves may be compromised. In this paper, a double-blind quantum identity authentication protocol based on scalar product computation is proposed. In the key generation stage, the scalar product of the two keys is stored in the database of a third-party platform. The two parties calculate the scalar product of their keys using a quantum private query (QPQ) protocol and compare the results with the expected results for authentication. Our protocol allows the two parties to be double-blind, i.e., they do not know each other's key. In this way, even if one party's key is leaked, the other party's key cannot be obtained.