A portable testing unit for biometric identity confirmation includes a housing with an orifice to receive a breath sample from the test subject, a spirometric sensor, and a pulse sensor adjacent to the orifice. A processor analyzes spirometric data from the spirometric sensor and simultaneous pulse wave data from the pulse sensor during the breath sample, together with stored subject characterization data for a known subject to confirm whether the identity of the test subject matches the known subject. A communications link enables the processor to communicate to the external station whether the identity of the test subject matches the known subject. For example, this portable testing unit can be used to control access to a secure facility or computer, authenticate the identity of a party in a financial transaction, or confirm the identity of the subject of an alcohol monitoring test.
