Optical multimodal biometric encryption that uses digital holography

Abstract In this paper, we propose an optical multimodal biometric encryption technique which uses digital holography (DH) for multiple biometric recording and successive optical encryption methods, by means of keys generated from biometric data. Physiological biometrics, such as fingerprints or iris scans, along with behavioral biometrics such as voice, are recorded simultaneously as multimodal biometrics, using multi-parameter off-axis DH. Moreover, multiple biometrics embedded in the same holograms are encrypted using the Fresnel domain double random phase encoding method, in which keys are generated from biometric data via a phase retrieval algorithm. By employing the decryption procedure for this encoding method, along with the correct keys and reconstruction parameters of DH, the original multimodal biometrics can be successfully retrieved . The proposed method provides multimodal biometrics with a higher level of security by availing itself of the advantages of optical techniques. Our proposed multimodal biometric security scheme is demonstrated and validated by the results of the optical recording and encryption of biometric data presented below.