[Paper Review] Practical self-testing QRNG based on an energy bound

Davide Rusca, Thomas van Himbeeck+6 more|arXiv (Cornell University)|Apr 9, 2019

Quantum Computing Algorithms and Architecture1 citations

TL;DR

This paper proposes a practical self-testing quantum random number generator (QRNG) that verifies device integrity in real time using a bounded mean energy per signal as a minimal assumption. Implementing a prepare-and-measure setup with off-the-shelf optical components, the scheme achieves a randomness generation rate of 1.25 Mbits/s, offering a strong balance between security, feasibility, and performance.

ABSTRACT

We present a scheme for a self-testing quantum random number generator. Compared to the fully device-independent model, our scheme requires an extra natural assumption, namely that the mean energy per signal is bounded. The scheme is self-testing, as it allows the user to verify in real-time the correct functioning of the setup, hence guaranteeing the continuous generation of certified random bits. Based on a prepare-and-measure setup, our scheme is practical, and we implement it using only off-the-shelf optical components. The randomness generation rate is 1.25 Mbits/s, comparable to commercial solutions. Overall, we believe that this scheme achieves a promising trade-off between the required assumptions, ease-of-implementation and performance.

Motivation & Objective

• To develop a self-testing QRNG that enables real-time verification of device integrity without full device independence.
• To reduce the assumptions required for device-independent randomness certification while maintaining security guarantees.
• To achieve a practical implementation using standard optical components for real-world deployability.
• To match or exceed the performance of commercial QRNG solutions in terms of randomness generation rate.

Proposed method

• The scheme employs a prepare-and-measure quantum communication setup to generate random bits using quantum states.
• A bounded mean energy per signal is assumed as a minimal physical constraint to enable self-testing without full device independence.
• Real-time verification of the device's correct operation is performed by monitoring energy constraints and measurement statistics.
• Off-the-shelf optical components such as lasers, beam splitters, and single-photon detectors are used to implement the setup.
• The randomness generation process is continuously monitored to ensure ongoing compliance with the energy bound and quantum principles.
• The protocol ensures certified randomness by verifying that observed statistics are consistent with quantum mechanical predictions under the energy constraint.

Experimental results

Research questions

• RQ1 Can a self-testing QRNG be practically implemented with minimal physical assumptions beyond standard quantum mechanics?
• RQ2 How can real-time device verification be achieved in a prepare-and-measure QRNG setup without full device independence?
• RQ3 What is the achievable randomness generation rate using off-the-shelf components under a bounded energy assumption?
• RQ4 To what extent does the energy-bound assumption reduce the required trust in the hardware while preserving security?

Key findings

• The proposed QRNG achieves a randomness generation rate of 1.25 Mbits/s, comparable to commercial solutions.
• The scheme enables real-time self-testing by verifying that the mean energy per signal remains within a predefined bound.
• The implementation uses only off-the-shelf optical components, demonstrating practical feasibility.
• The energy-bound assumption reduces the need for strong device-independent assumptions while still ensuring certified randomness.
• The method successfully balances security, practicality, and performance, offering a viable alternative to fully device-independent QRNGs.