Post-Quantum Wireless-based Key Encapsulation Mechanism via CRYSTALS-Kyber for Resource-Constrained Devices

Abstract: We consider the problem of adapting a Post-Quantum cryptosystem to be used in resource-constrained devices, such as those typically used in Device-to-Device and Internet of Things systems. In particular, we propose leveraging the characteristics of wireless communications channels to minimize the complexity of implementation of a Post-Quantum public key encryption scheme, without diminishing its security. To that end, we focus on the adaptation of a well-known cryptosystem, namely CRYSTALS-Kyber, so as to enable its direct integration into the lowest layer of the communication stack, the physical layer, defining two new transport schemes for CRYSTALS-Kyber to be used in Device-to-Device communications, both of which are modeled under a wireless channel subject to Additive White Gaussian Noise, using a 4 Quadrature Amplitude Modulation constellation and a BCH-code to communicate CRYSTALSKyber's polynomial coefficients. Simulation results demonstrate the viability of the adapted Kyber algorithm due to its low key error probability, while maintaining the security reductions of the original Kyber by considering the error distribution imposed by the channel on the cipher.