[m8urn]

The problem is that fingerprint matching isn't exact, there are thresholds you must allow for so there is no exact code to match to. Although some implementations may make this possible, it is an issue that all biometric methods must address.

It's like allowing a password that is close enough, in that case you would need the real password as well, not just a hash.

[semenko]

Sure, though there are simhash implementations, where you can compute a hash that itself can be used to compute a hamming distance between two inputs.

(This is used a fair amount in search, to cluster similar documents.)