Multimodal biometric Identity Based Encryption

In order to have high recognition rate and thus increased possibility of decryption even in case of white noise (slight perturbation of biometric features), our generic construction is based on two different biometric IBE systems encoding the same message. This way, employment of both distance measures is possible using multiple matchers within multimodal setting and a failure on the decryption of a message encrypted using the first biometric representation, can be compensated with an attempt on the second part of the ciphertext encrypting the same message but using a different representation of the same receiver. Specifically, we combine a fuzzy IBE-type scheme and the recently introduced Distance Based Encryption (DBE) scheme with minimum overhead in terms of public parameters, ciphertext and private key size. For this purpose, we describe an efficient biometric IBE scheme denoted as ordFIBE, which is restricted for biometrics that can be represented as an ordered/grouped set of features. We study the security of ordFIBE both in random oracle model (ROM) and for small universe of attributes in standard model. In ROM, its efficiency is further improved by employing online/offline encryption technique. Next, we instantiate the new construction by combining ordFIBE and the DBE scheme of Guo et al. (2014), which shares the same setup phase, in particular, common public parameters. Finally, we describe a new scheme for set difference metric that partially solves an open problem introduced in Katz et al. (2008).