PHY-PSIONICS: Physical-Layer Phase Secret Key Encapsulation in Correlated Subchannels

Abstract

In this letter, we propose a physical-layer (PHY) phase secret key encapsulation in correlated subchannels, PHY-PSIONICS. Based on the PHY phase challenge-response authentication scheme (PHY-PCRAS), conventional PHY authentication approaches generally exploit the channel phase’s reciprocity to encapsulate the secret key. However, for typical multi-carrier systems, correlations between neighboring subcarriers could cause these schemes to lose credibility. Therefore, we propose a novel key encapsulation scheme to allow PHY phase-based authentication in practical multi-carrier systems. The shared secret key is efficiently encapsulated by the binning-based multi-bit alphabet phase fingerprinting. We constructed a testbed with several universal software radio peripherals for verification to evaluate the authentication performance experimentally in an indoor environment containing correlated subchannels. The numerical findings demonstrate that the proposed scheme is strong against eavesdropping and replay attacks, even under subchannel correlations.