In the spirit of device-independent cryptography, we present a two-party quantum authorization primitive with nonlocality as its fueling resource. Therein, users are attributed authorization levels granting them access to a private database accordingly. The authorization levels are encoded in the nonlocal resources distributed to the users and subsequently confirmed by their ability to win Clauser-Horne-Shimony-Holt games using such resources. We formalize the protocol, prove its security, and frame it in a device-independent setting employing the notion of Clauser-Horne-Shimony-Holt self-testing via simulation. Finally, we provide a proof-of-concept implementation using the Qiskit open-source framework.

• Received 4 November 2020
• Accepted 8 February 2021

DOI:https://doi.org/10.1103/PhysRevA.103.022430