There is a cryptographic tool called a "fuzzy extractor" that solves this problem (c.f. Fuzzy Extractors: How to Generate Strong Keys from Biometrics and Other

There is a cryptographic tool called a "fuzzy extractor" that solves this problem (c.f. Fuzzy Extractors: How to Generate Strong Keys from Biometrics and Other Noisy Data, by Dodis, Reyzen and Smith [0]). At enrollment time, you compute some (non-sensitive) data P = Enroll(biometric). Then every time you compute Recover(P, biometric') you will get the same (high-entropy) output, as long as biometric' is close enough to biometric. [0] https://www.iacr.org/archive/eurocrypt2004/30270518/DRS-ec2004-final.pdf https://www.iacr.org/archive/eurocrypt2004/30270518/DRS-ec20...