A biometric identity confirmation system is based on pulse waveform data for the subject (20). During an initial enrollment mode, pulse waveform data for a known subject (20) are used to generate subject characterization data (23) for the known subject (20). The subject characterization data (23) includes an exemplar created by synchronous averaging of pulse waveform data over multiple puise cycles. A number of trigger candidates are identified for the start point of each pulse cycle. The time delay between trigger candidates is analyzed to discard faise trigger candidate and identify true candidates, which are then used as the start points for each pulse cycle in synchronous averaging of the pulse waveform data. During a subsequent identity authentication mode, pulse waveform data for a test subject (25) are analyzed using the subject characterization data (23) to confirm whether the identity of the test subject (25) matches the known subject (20).
