There is an increased concern over the loss of
privacy and potential misuse of biometric data held
in central repositories. The major concerns are
about the use of biometrics to track people, the non-
revocability of biometrics (if compromised they can
not be canceled or reissued), and disclosure of
sensitive information such as race and health
problems. The suggestion of keeping the biometric
data in a user owned token does not completely solve
the problem, as malicious users can claim that their
token is broken to avoid biometric verification.
Overall, these concerns brought the need for privacy
preserving biometric authentication methods in the
recent years. This book analyses existing privacy
preserving biometric systems and provides a novel
framework, which combines multiple biometric traits
to obtain a multi-biometric template that hides the
constituent biometrics and allows the possibility of
creating non-unique identifiers for a person, such
that linking separate template databases is
impossible. The book should be a useful reference
for those interested in a contemporary technology to
remedy privacy issues raised by the widespread of
biometric systems.