  The fuzzy vault is an error tolerant authentication method that ensures the
privacy of the stored reference data. Several publications have proposed the
application of the fuzzy vault to fingerprints, but the results of subsequent
analyses indicate that a single finger does not contain sufficient information
for a secure implementation. In this contribution, we present an implementation
of a fuzzy vault based on minutiae information in several fingerprints aiming
at a security level comparable to current cryptographic applications. We
analyze and empirically evaluate the security, efficiency, and robustness of
the construction and several optimizations. The results allow an assessment of
the capacity of the scheme and an appropriate selection of parameters. Finally,
we report on a practical simulation conducted with ten users.
