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Quantum random number generation from the continuous variable payload for the SPOQC mission

Vinod N. Rao, Killian Murphy, Fadi Ahwal, Emma Tien Hwai Medlock, Timothy P. Spiller, Rupesh Kumar

TL;DR

This work reports a continuous-variable quantum random number generator (CV-QRNG) implemented in the SPOQC satellite payload, exploiting vacuum fluctuations measured by a shot-noise-limited homodyne detector. It develops a security framework based on the conditional min-entropy $H_{ ext{min}}$ and entropic uncertainty principles, and uses Toeplitz hashing to extract $\\\e$-secure randomness from discretized quadrature data. Empirical results show entropy bounds for 12-bit and 16-bit ADC configurations, validation with the NIST randomness suite, and extraction of about $19.5$ kb of certified randomness from a raw $\\approx 1$ Mb per pass. The method integrates with the SPOQC CV-QKD hardware, enabling secure randomness for downlink quantum communications and representing the first space-based CV-QRNG demonstration planned for launch in early 2026.

Abstract

The necessity of random numbers for various tasks, from simulation to cryptography, is crucial and immense. Here we demonstrate CV-QRNG using the CV payload of the SPOQC mission. The homodyne setup for QRNG uses the laser from the payload, in addition to potentially being used as detector in the case of an uplink scenario. Here we quantify the extractable secure randomness from the QRNG setup, that involves homodyne measurement of the vacuum states. The extracted randomness is tested against NIST test suite in addition to formally upper bounding the min-entropy. With the raw key length being $\approx1$ Mb in a given satellite pass, we get a total length of $\approx19.5$ Kb of certified random numbers from the 12-bit ADC.

Quantum random number generation from the continuous variable payload for the SPOQC mission

TL;DR

This work reports a continuous-variable quantum random number generator (CV-QRNG) implemented in the SPOQC satellite payload, exploiting vacuum fluctuations measured by a shot-noise-limited homodyne detector. It develops a security framework based on the conditional min-entropy and entropic uncertainty principles, and uses Toeplitz hashing to extract -secure randomness from discretized quadrature data. Empirical results show entropy bounds for 12-bit and 16-bit ADC configurations, validation with the NIST randomness suite, and extraction of about kb of certified randomness from a raw Mb per pass. The method integrates with the SPOQC CV-QKD hardware, enabling secure randomness for downlink quantum communications and representing the first space-based CV-QRNG demonstration planned for launch in early 2026.

Abstract

The necessity of random numbers for various tasks, from simulation to cryptography, is crucial and immense. Here we demonstrate CV-QRNG using the CV payload of the SPOQC mission. The homodyne setup for QRNG uses the laser from the payload, in addition to potentially being used as detector in the case of an uplink scenario. Here we quantify the extractable secure randomness from the QRNG setup, that involves homodyne measurement of the vacuum states. The extracted randomness is tested against NIST test suite in addition to formally upper bounding the min-entropy. With the raw key length being Mb in a given satellite pass, we get a total length of Kb of certified random numbers from the 12-bit ADC.

Paper Structure

This paper contains 3 sections, 17 equations, 8 figures, 1 table.

Table of Contents

  1. Introduction
  2. CV-QRNG
  3. Discussions and conclusions

Figures (8)

  • Figure 1: Homodyne measurement of two signals. S - Shutter; LO - Local Oscillator; BS - Beam-Splitter; PD - Photo-Detector; TIA - Trans-Impedance Amplifier; ADC - Analog-to-Digital Converter; SBC - Single Board Computer.
  • Figure 2: An abstract block diagram of the CV payload and receiver for the SPOQC mission. Gaussian modulated coherent states are created using amplitude and phase modulator (AM & PM) and sent to the optical ground station (OGS). A beam-splitter (BS) is used to send some part of signal and/or LO to QRNG receiver module. HD is the homodyne detector.
  • Figure 3: Probability distributions of the shot noise. The colours represent three data sets.
  • Figure 4: Probability distributions of the electronic noise. The dashed (dotted) line corresponds to output from 12-bit (16-bit) ADC.
  • Figure 5: Respective entropy values.
  • ...and 3 more figures