A Composable Multifactor Identity Authentication and Authorization Scheme for 5G Services

Algorithm 4

Password update.

	Require: the user identity ; the password ; the biometric data ; the smart card.
	Ensure: update the result: 0 for failure; 1 for success.
(1)	and user execute the mutual authentication process. The security level is set to 3. If authentication failed, Output 0. Otherwise, go ahead.
(2)	User works as follows.
(i)	Choose a new password , and the smart card generates new to compute .
(ii)	Send , password update request to .
(3)	Upon the receipt of the message, works as follows.
(i)	Derive from .
(ii)	Choose as well as , and calculate .
(iii)	Calculate .
(iv)	Send to .
(4)	Upon the receipt of the message, computes .
(5)	and store , , and to replace the old information. And Output 1.