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

Algorithm 2

Session key agreement.

	Require: the user identity ; the password ; the biometric data ; the smart card.
	Ensure: agreement result: .
(1)	executes the following commands.
(i)	Check the highest security level in the authentication process. If, then Output 1, and Terminate the process. Else, go ahead.
(ii)	Choose random number .
(iii)	Compute the secret auxiliary message
	If, then set
	.
	If, then set
	.
	If, then set
	.
(iv)	Calculate .
(v)	Send to .
(2)	Upon the receipt of the message, works as follows.
(i)	Choose random number .
(ii)	Compute the secret auxiliary message .
	If, then sets
	.
	If, then sets
	.
	If, then sets
	.
(iii)	Calculate .
(iv)	Calculate .
(v)	Send to .
(3)	Upon the receipt of the message, works as follows.
(i)	Calculate .
(ii)	Decrypt with . And if the decryption is , confirms success.
(iii)	Send to .
(4)	decrypts with . And if the decryption is , confirms success, and the process terminates.