Step 1	As shown in the Section 2.1, Uα selects IDα and pwα.
Step 2	Uα computes H_PWα=h(pwα).
	Uα sends the registration request {IDα, h(pwα)} to GW.
Step 3	GW computes the following when it receives the registration request from Uα.
	Aα = h(IDα∥H_PWα∥xs)⊕h(K)
	Bα=h(H_PWα⊕xs)
	Cα=xs ⊕ h(IDs∥H_PWα)
	GW personalizes the smart card with IDs, IDα, h(·), Aα, Bα and Cα.
	GW sends the smart card to Uα.
Step 4	Uα reads IDs, IDα, Aα, Bα, and Cα from the smart card.
	Uα can know xs and h(K) by computing the following.
	xs= Cα ⊕ h(IDs∥H_PWα)
	h(K) = Aα ⊕ h(IDα∥H_PWα∥ xs)