Traceable random numbers from a nonlocal quantum advantage

TL;DR

This paper introduces a novel protocol for generating fully traceable and certifiable quantum random numbers using device-independent techniques and non-local quantum correlations, enabling secure and auditable randomness for public use.

Contribution

It presents the first fully traceable quantum random number generation protocol that combines device-independent methods with cryptographic traceability, operationalized as a public randomness beacon.

Findings

Achieved a 99.7% success rate over 40 days with 7434 successful outputs

Generated 512 bits of traceable randomness per successful attempt

Certified randomness with an error bound of 2^{-64}

Abstract

The unpredictability of random numbers is fundamental to both digital security and applications that fairly distribute resources. However, existing random number generators have limitations-the generation processes cannot be fully traced, audited, and certified to be unpredictable. The algorithmic steps used in pseudorandom number generators are auditable, but they cannot guarantee that their outputs were a priori unpredictable given knowledge of the initial seed. Device-independent quantum random number generators can ensure that the source of randomness was unknown beforehand, but the steps used to extract the randomness are vulnerable to tampering. Here, for the first time, we demonstrate a fully traceable random number generation protocol based on device-independent techniques. Our protocol extracts randomness from unpredictable non-local quantum correlations, and uses distributed intertwined hash chains to cryptographically trace and verify the extraction process. This protocol is at the heart of a public traceable and certifiable quantum randomness beacon that we have launched. Over the first 40 days of operation, we completed the protocol 7434 out of 7454 attempts -- a success rate of 99.7%. Each time the protocol succeeded, the beacon emitted a pulse of 512 bits of traceable randomness. The bits are certified to be uniform with error times actual success probability bounded by $2^{-64}$. The generation of certifiable and traceable randomness represents one of the first public services that operates with an entanglement-derived advantage over comparable classical approaches.