  In this paper, we provide an overview of fingerprint sensing methods used for
authentication. We analyze the current fingerprint sensing technologies, from
algorithmic, as well as from hardware perspectives. We then focus on methods to
detect physical liveness, defined as techniques that can be used to ensure that
a living human user is attempting to authenticate on a system. We analyze how
effective these methods are at preventing attacks where a malicious entity
tries to trick a fingerprint-based authentication system to accept a fake
finger as a real one (spoofing attacks). We then identify broader attack points
against biometric data, such as fingerprints. Finally, we propose novel
measures to protect fingerprint data.
