Abstract: Described are various embodiments of a digital user authentication device to authenticate an authorized user. The device comprises a wearable user authentication interface operable to receive unique user identification data and a finger physiological signal; an onbody physiological sensor operable to simultaneously acquire a distinct onbody physiological signal; and a digital data processor operable to execute a user authentication process based on the unique user identification data while confirming a user presence based on the finger physiological signal, and further digitally compare the finger physiological signal and the distinct onbody physiological signal to automatically confirm that they match within a designated level of confidence so to confirm that they were both acquired from a same user.