First demonstration of a post-quantum key-exchange with a nanosatellite

TL;DR

This paper reports the first successful demonstration of a post-quantum key exchange on a nanosatellite in orbit, using Kyber-512, showing feasibility for quantum-safe satellite communications.

Contribution

It presents the first in-orbit implementation of a post-quantum key exchange protocol on a nanosatellite, using Kyber-512 and a low-power microcontroller.

Findings

Successful in-orbit key exchange using Kyber-512

Firmware runs on a widely used microcontroller platform

Shared secret could enable quantum-safe encryption in space

Abstract

We demonstrate a post-quantum key-exchange with the nanosatellite SpooQy-1 in low Earth orbit using Kyber-512, a lattice-based key-encapsulation mechanism and a round three finalist in the NIST PQC standardization process. Our firmware solution runs on an on-board computer that is based on the Atmel AVR32 RISC microcontroller, a widely used platform for nanosatellites. We uploaded the new firmware with a 436.2 MHz UHF link using the CubeSat Space Protocol (CSP) and performed the steps of the key exchange in several passes over Switzerland. The shared secret key generated in this experiment could potentially be used to encrypt RF links with AES-256. This implementation demonstrates the feasibility of a quantum-safe authenticated key-exchange and encryption system on SWaP constrained nanosatellites.