A protocol for the secure two-party quantum scalar product

Secure scalar product serves as an important primitive for secure multi-party computation and has a wide application in different areas, such as statistical analysis, data mining, computational geometry, etc. How to collaboratively compute the correct scalar product result without leaking any participantsʼ private information becomes the primary principle of designing secure scalar product schemes. In this Letter, we present a secure two-party quantum scalar product scheme via quantum entanglement and quantum measurement with the help of a non-colluding third party (TP). Furthermore, the scheme is proven to be secure under various kinds of outside attacks and participant attacks.

► We extend the secure two-party scalar product to the quantum field.
► Our protocol is built upon quantum entanglement and quantum measurement.
► Communication cost is acceptable if the elements of participantsʼ private vectors are not too sparse.
► Participants will leak no private information under the no-collusion model.