Source-independent quantum random number generation

TL;DR

This paper introduces a source-independent quantum random number generation scheme that certifies randomness without trusting the source, demonstrating practical implementation with a high generation rate.

Contribution

The authors propose a novel source-independent scheme for quantum random number generation that does not require assumptions about the source's dimension or trustworthiness.

Findings

Achieved a randomness generation rate of over 5000 bits per second.

Certified randomness even with uncharacterized and untrusted sources.

Validated the scheme through experimental modification of a quantum key distribution system.

Abstract

Quantum random number generators can provide genuine randomness by appealing to the fundamental principles of quantum mechanics. In general, a physical generator contains two parts---a randomness source and its readout. The source is essential to the quality of the resulting random numbers; hence, it needs to be carefully calibrated and modeled to achieve information-theoretical provable randomness. However, in practice, the source is a complicated physical system, such as a light source or an atomic ensemble, and any deviations in the real-life implementation from the theoretical model may affect the randomness of the output. To close this gap, we propose a source-independent scheme for quantum random number generation in which output randomness can be certified, even when the source is uncharacterized and untrusted. In our randomness analysis, we make no assumptions about the dimension of the source. For instance, multiphoton emissions are allowed in optical implementations. Our analysis takes into account the finite-key effect with the composable security definition. In the limit of large data size, the length of the input random seed is exponentially small compared to that of the output random bit. In addition, by modifying a quantum key distribution system, we experimentally demonstrate our scheme and achieve a randomness generation rate of over $5\times 10^3$ bit/s.