Here's my two cents.
I'm the founder of a biometric users identity check solution, called Typing AI Biometrics ( https://typing.ai ). We identify users by the way they type. Typing biometrics can be used as a two factor (2FA) or multi factor (MFA) authentication method.
Instead of combining the usual username + password with an OTP code that you recive on your smartphone or email, you can combine the basic username + password with a typing pattern check, it's much more secure and efficient. The typing signature translated into a 300+ encrypted characters hash, which is (up until now) impossible to break.
You can even remove the username + password and combine the typing biometrics check (known as keystroke dynamics) with an OTP verification. Biometrics are the future of authentication and authorization, because they are unique to each person, but only with the promise of not keeping and sharing the users data.
You can AMA on this Show HN thread: https://news.ycombinator.com/item?id=30130447