Many site use time-based one time password (totp) as second factor auth method, such as aws.
So we can split the totp secret and distribute each part to different party to achieve threshold login ( need at least k parties to login ).
We can split secret using shamir secret share scheme, but the problem is when we need to get current pin, we need to reconstruct the secret. Is there any method to do something similar without revealing each one's secret part?
General multiparty computation seems to be a method. But I can't find any practical implementation to do hmac-sha1 algorithm.