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cern that consumers may find the ap-
proach inconvenient.
We also show multimodal biomet-
rics can be integrated with mobile
devices in a user-friendly manner
and significantly improve their secu-
rity. In 2015, we thus implemented a
multimodal biometric system called
Proteus at California State University,
Fullerton, based on face and voice
on an Samsung Galaxy S5 phone, in-
tegrating new multimodal biometric
authentication algorithms optimized
for consumer-level mobile devices
and an interface that allows users
to readily record multiple biometric
traits. Our experiments confirm it
achieves considerably greater authen-
tication accuracy than systems based
solely on face or voice alone. The next
step is to integrate other biometrics
(such as fingerprints and iris scans)
into the system. We hope our experi-
ence encourages researchers and mo-
bile-device manufacturers to pursue
the same line of innovation.
Biometrics
Biometrics-based authentication es-tablishes identity based on physical
and behavioral characteristics (such
as face and voice), relieving users from
having to create and remember secure
passwords. At the same time, it challenges attackers to fabricate human
traits that, though possible, is difficult
in practice.
21 These advantages continue to spur adoption of biometrics-based authentication in smartphones
and tablet computers.
Despite the arguable success of biometric authentication in mobile devices,
several critical issues remain, including,
for example, techniques for defeating
iPhone TouchID and Samsung Galaxy
S5 fingerprint recognition systems.
2, 26
Further, consumers continue to complain that modern mobile biometric
systems lack robustness and often fail to
recognize authorized users.
4 To see how
multimodal biometrics can help address these issues, we first examine their
underlying causes.
The Mobile World
One major problem of biometric authentication in mobile devices is sample quality. A good-quality biometric
sample—whether a photograph of
a face, a voice recording, or a fingerprint scan—is critical for accurate
identification; for example, a low-resolution photograph of a face or