  A new method to generate gummy fingers is presented. A medium-size fake
fingerprint database is described and two different fingerprint verification
systems are evaluated on it. Three different scenarios are considered in the
experiments, namely: enrollment and test with real fingerprints, enrollment and
test with fake fingerprints, and enrollment with real fingerprints and test
with fake fingerprints. Results for an optical and a thermal sweeping sensors
are given. Both systems are shown to be vulnerable to direct attacks.
