Every security system relies on some secrecy to function. For example, we keep passwords and private keys secret for a reason. The question is what pieces sh

Every security system relies on some secrecy to function. For example, we keep passwords and private keys secret for a reason. The question is what pieces should be kept secret. Biometrics has a pretty impressive false positive rate, so are generally considered the weakest form of strong security. But this then brings one to the heart of the problem.