  Human users have a tough time remembering long cryptographic keys. Hence,
researchers, for so long, have been examining ways to utilize biometric
features of the user instead of a memorable password or passphrase, in an
effort to generate strong and repeatable cryptographic keys. Our objective is
to incorporate the volatility of the user's biometric features into the
generated key, so as to make the key unguessable to an attacker lacking
significant knowledge of the user's biometrics. We go one step further trying
to incorporate multiple biometric modalities into cryptographic key generation
so as to provide better security. In this article, we propose an efficient
approach based on multimodal biometrics (Iris and fingerprint) for generation
of secure cryptographic key. The proposed approach is composed of three modules
namely, 1) Feature extraction, 2) Multimodal biometric template generation and
3) Cryptographic key generation. Initially, the features, minutiae points and
texture properties are extracted from the fingerprint and iris images
respectively. Subsequently, the extracted features are fused together at the
feature level to construct the multi-biometric template. Finally, a 256-bit
secure cryptographic key is generated from the multi-biometric template. For
experimentation, we have employed the fingerprint images obtained from publicly
available sources and the iris images from CASIA Iris Database. The
experimental results demonstrate the effectiveness of the proposed approach.
