Abstract
An emerging approach to the problem of reducing the identity theft
is represented by the adoption of biometric authentication systems.
Such systems however present however several challenges, related
to privacy, reliability, security of the biometric data. Inter-operability
is also required among the devices used for the authentication. Moreover,
very often biometric authentication in itself is not sufficient
as a conclusive proof of identity and has to be complemented with
multiple other proofs of identity like passwords, SSN, or other user
identifiers. Multi-factor authentication mechanisms are thus required
to enforce strong authentication based on the biometric and
identifiers of other nature.
In this paper we provide a two-phase authentication mechanism
for federated identity management systems. The first phase consists
of a two-factor biometric authentication based on zero knowledge
proofs. We employ techniques from vector-space model to generate
cryptographic biometric keys. These keys are kept secret, thus
preserving the confidentiality of the biometric data, and at the same
time exploit the advantages of a biometric authentication. The second
authentication combines several authentication factors in conjunction
with the biometric to provide a strong authentication. A
key advantage of our approach is that any unanticipated combination
of factors can be used. Such authentication system leverages
the information of the user that are available from the federated
identity management system.
