1. A multifactor authentication system comprising: a sheet prism or other prism means; a light source; a non-spectrometric biometric signature acquisition means, acquiring at least a single fingerprint image of a fingertip of a person to be authenticated and comprising a CCD or CMOS sensor and a first optical system, in turn comprising at least a first lens and forming the fingerprint image on the CCD or CMOS sensor; a spectral information acquisition means, acquiring at least a single diffuse reflectance spectrum of the fingertip and comprising a photodiode array (PDA) and a second optical system, in turn comprising at least a second lens and a diffraction grating and spectrally dispersing diffusely reflected light from the fingertip onto the PDA; and an identity determination and verification means, comprising a computer or other information processing means and using the fingerprint image to determine the unique identity of the person to be authenticated and using the diffuse reflectance spectrum of the fingertip to verify that the person to be authenticated is a living human being with predetermined spectral characteristics; and wherein the fingertip is placed on said sheet prism or other prism means, light from said light source is made incident on the fingertip via the sheet prism or other prism means, and said first optical system forms an image of the spectrally reflected light from the fingertip on the CCD or CMOS sensor at the same time that said second optical system spectrally disperses the diffusely reflected light from the fingertip onto the PDA so that the fingerprint image and the diffuse reflectance spectrum of the fingertip are acquired simultaneously.