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There are ways to use error-correcting codes to turn probabilistic samples into deterministic ones and mix them with a key. These are constructed so that you ga
by someguyorother 6y ago
There are ways to use error-correcting codes to turn probabilistic samples into deterministic ones and mix them with a key. These are constructed so that you gain no information if you only know the key, or only know the biometric. See https://en.wikipedia.org/wiki/Fuzzy_extractor https://en.wikipedia.org/wiki/Fuzzy_extractor.
- motohagiography 6y agoGreat papers linked from that. At the time, it seemed the sensor APIs didn't provide a key with sufficient entropy to be considered a cryptographic verification for the tokens we were using. We didn't take it further because the entropy of the biometric sample was going to be diminished by using it to generate a static key, even though the papers linked show you can compose a key with error correcting codes, and intuitively, you could use some kind of probabilistic filter to verify a set of bits in the sample via shamir secret sharing to provide a threshold for a key. It still relies on separate security domains between the biometric sample collection and the cryptographic verifier, and we'd be deep in to the engineering over the differences, but these papers are really useful for getting into the details. One of the early ones was a good intro to it: http://people.csail.mit.edu/madhu/papers/2002/ari-journ.pdf http://people.csail.mit.edu/madhu/papers/2002/ari-journ.pdf