1. A method of performing a biometric function, the method comprising: illuminating a small-area purported skin site of an individual with illumination light; receiving light scattered from the small-area purported skin site; generating a local feature profile from the received light, wherein the local feature profile identifies a feature of the small-area purported skin site, the feature of the small-area purported skin site being of a type predetermined to exhibit substantial local consistency; and analyzing the generated local feature profile to perform the biometric function, wherein analyzing the generated local feature profile comprises comparing the generated local feature profile with a reference local feature profile, wherein the reference local feature profile was generated from light scattered from a small-area reference skin site, and wherein the small-area purported skin site is substantially different from the small-area reference skin site.