Radio Frequency Impedance Interrogation (RFII) measures hemodynamic function via resonance frequency coupling to a hydrophilic protein molecule and the resonant return signal phase change. The RFII device generates a cardiosynchronous waveform from the identification of blood movement in the time, frequency, and voltage domains. While the application of this technology to hemodynamic monitoring has demonstrated initial success, this small pilot study examined the use of RFII for subject identification by cardiosynchronous waveform signal analysis, which would allow confirmation of the identity of a subject in an operational setting. Preliminary results demonstrate 86% successful subject identification using the RFII cardiosynchronous waveform signature and simple pattern recognition classification, with as high as 100% identification with improvements to phase-shift recognition. Each individual appears to have a unique waveform morphology that is visually distinct from the other individuals in the data set. These results suggest that RFII may hold great potential as a biometric identifier and the rapid identification and authentication of subjects in the operational setting.