Argument on biometrics identity-based encryption schemes

Recently, a few biometric identity-based encryption (BIO-IBE) schemes have been proposed. BIO-IBE leverages both fuzzy extractor and Lagrange polynomial to extract biometric feature as a user public key and as a preventive measure of collusion attack, respectively. In this paper, we reveal that BIO-IBE is not realistic whereby a query of fresh biometrics is needed for each encryption process. Moreover, the use of both fuzzy extractor and Lagrange polynomial in BIO-IBE simultaneously is a redundancy; it confers no advantage, but simply computational overhead. Therefore, we amend the progression of the BIO-IBE scheme by eliminating either Lagrange polynomial or fuzzy extractor to alleviate computational complexity. Subsequently, we demonstrate that the amendment does not compromise the security of the BIO-IBE scheme. Such amendments can be applied to other BIO-IBE schemes as well.