A quantum random number generator on a nanosatellite in low Earth orbit

Quantum random number generators find applications in both quantum and classical communications schemes, particularly in security protocols where they can be used as a source of random seed or key material. In this work, we describe the implementation of a quantum random number generator on-board a nanosatellite deployed in low Earth orbit. Our generator samples shot noise from an entangled photon-pair source based on spontaneous parametric down-conversion, linking the entropy of the output to the quantization of the down-converted beam. We present analyzed data from the orbiting instrument alongside data taken from a ground-based engineering model where the statistical test suites indicate a good match to the output from a uniform distribution. Finally, we use the source to implement a prototype for an off-grid randomness beacon. This work paves the way to future low Earth orbit based public quantum randomness beacons. Quantum Random Number Generators (QRNG) are important components of cryptographic protocols including prepare-and-measure based quantum key distribution protocols. The authors demonstrate laboratory, as well as in-orbit operation of their QRNG, showing its use to implement a public randomness beacon.