  In a biometric verification system, leakage of biometric data leads to
permanent identity loss since original biometric data is inherently linked to a
user. Further, various types of attacks on a biometric system may reveal the
original template and utility in other applications. To address these security
and privacy concerns cancelable biometric has been introduced. Cancelable
biometric constructs a protected template from the original biometric template
using transformation functions and performs the comparison between templates in
the transformed domain. Recent approaches towards cancelable fingerprint
generation either rely on aligning minutiae points with respect to singular
points (core/delta) or utilize the absolute coordinate positions of minutiae
points. In this paper, we propose a novel non-invertible ridge feature
transformation method to protect the original fingerprint template information.
The proposed method partitions the fingerprint region into a number of sectors
with reference to each minutia point employing a ridge-based co-ordinate
system. The nearest neighbor minutiae in each sector are identified, and
ridge-based features are computed. Further, a cancelable template is generated
by applying the Cantor pairing function followed by random projection. We have
evaluated our method with FVC2002, FVC2004 and FVC2006 databases. It is evident
from the experimental results that the proposed method outperforms existing
methods in the literature. Moreover, the security analysis demonstrates that
the proposed method fulfills the necessary requirements of non-invertibility,
revocability, and diversity with a minor performance degradation caused due to
cancelable transformation.
