1. A method comprising: collecting a plurality of one type of biometric measurements of a user; computing a first confidence measure from the biometric measurements according to a first algorithm and a second confidence measure from the biometric measurements according to a second algorithm, wherein the first confidence measure is based on at least two of: a) string complexity based on a length of the string, repeated letters of the string, and repeated sequences of letters of the string, b) biometric template maturity based on a time elapsed since template creation, a time elapsed since the latest template update, a frequency with which the template has been used, and a frequency with which the template has been updated, and c) engine initial confidence based on an authentication scoring history of the user; and wherein the second confidence measure is based on at least two of: a) string complexity based on a length of the string, repeated letters of the string, and repeated sequences of letters of the string, b) biometric template maturity based on a time elapsed since template creation, a time elapsed since the latest template update, a frequency with which the template has been used, and a frequency with which the template has been updated, and c) engine initial confidence based on an authentication scoring history of the user; and preparing a unified confidence measure from weighed inputs including the first confidence measure and the second confidence measure.