1. Lightweight IoT-based authentication scheme in cloud computing circumstance
Source: Future Generation Computer Systems Volume 91, February 2019, Pages
Authors: Lu Zhou , Xiong Li , Kuo-Hui Yeh , Chunhua Su , Wayne Chiu
Speaker: Yao-Zhu Zheng
Date: 2018/11/22

2. Outline
Introduction
Proposed scheme
Experimental results
Conclusions

3. Introduction Server User Control Server Require Authentication
Response
Server
2.Smart card
User
Control Server
1.Registration

4. Proposed scheme (1/13)
Registration
Authentication
Password change

5. Proposed scheme (2/13) Registration
User registration
Cloud server registration
2.Data for Authentication
Server
1.Registration
2.Smart card
User
Control Server
1.Registration

6. Proposed scheme (3/13)

7. Proposed scheme (4/13) Registration – User registration
Control Server
select (IDi , PIDi) , PWi , bi HPi = h(PWi ∥ bi) send (IDi , PIDi) to CS
CS check IDi
C1* = h(PIDi ∥ IDcs ∥ x )
C2* = h(IDi ∥ x )
store IDi in database, send(C1* , C2* , IDcs) to Ui
C1 = C1* ⊕ HPi
C2 = C2* ⊕ h(IDi ∥ HPi )
C3 = bi ⊕ h(IDi ∥ PWi )
Store (C1 , C2 , C3 , PIDi , IDcs) in smart card

8. Proposed scheme (5/13) Registration – Cloud server registration
Control Server
Server
send (SIDj ,PSIDj) to CS
CS computes B1 = h(PSIDj ∥ IDcs ∥ x ) B2 = h(SIDj ∥ x ) store SIDj and send (B1 , B2 , IDcs) to Sj
Sj store (B1 , B2 , SIDj, PSIDj, IDcs)

9. Proposed scheme (6/13) Authentication
Server M4 M3
User
Control Server

10. Proposed scheme (7/13) Authentication
Ui Input IDi , PWi select ru, PIDinew bi = C3 ⊕ h(IDi ∥ PWi ) HPi = h(PWi ∥ bi) C1* = C1 ⊕ HPi C2* = C2 ⊕ h (IDi ∥ HPi ) D1 = C1* ⊕ ru D2 = h(ru ∥ PIDi ∥ IDcs) ⊕ IDi D3 = C2* ⊕ h (IDi ∥ HPi ) ⊕ PIDinew ⊕ h(ru ∥ IDi ) D4 = h(IDi ∥ PIDi ∥ PIDinew ∥ ru ∥ D3) M1 = {PIDi , D1 , D2 , D3 , D4} Pass M1 to Sj
User

11. Proposed scheme (8/13) Authentication
Sj select PSIDjnew , rs D5 = B1 ⊕ rs D6 = h(rs ∥ PSIDj ∥ IDcs ) ⊕ SIDj D7 = B2 ⊕ PSIDjnew ⊕ h(rs ∥ PSIDj ) D8 = h(SIDj ∥ PSIDj ∥ PSIDjnew ∥ rs ∥ D7 ) M2 = {PIDi , D1 , D2 , D3 , D4 , PSIDj , D5 , D6 , D7 , D8} Pass M2 to CS
Server

12. Proposed scheme (9/13) Authentication
CS ru = D1 ⊕ h(PIDi ∥ IDcs ∥ x ) IDi = D2 ⊕ h (ru ∥ PIDi ∥ IDcs) PIDinew = D3 ⊕ h(IDi ∥ x ) ⊕ h (ru ∥ IDi ) check IDi check D4 ?= h (IDi ∥ PIDi ∥ PIDinew ∥ ru ∥ D3) rs = D5 ⊕ h(PSIDj ∥ IDcs ∥ x ) SIDj = D6 ⊕ h(rs ∥ PSIDj ∥ IDcs ) PSIDjnew = D7 ⊕ h(SIDj ∥ x ) ⊕ h(rs∥ SIDj ) check SIDj check D8 ?= h (SIDj ∥ PSIDj ∥ PSIDjnew ∥ rs ∥ D7)
Control Server

13. Proposed scheme (10/13) Authentication
CS select rcs SKcs = h (ru ⊕ rs ⊕ rcs) D9 = h(PSIDjnew ∥ IDcs ∥ x ) ⊕ h (rs ∥ PSIDjnew ) D10 = h(PSIDjnew ∥ rs ∥ PSIDj ) ⊕ (ru ⊕ rcs ) D11 = h(SKcs ∥ D9 ∥ D10 ∥ h (SIDj ∥ x ) ) D12 = h(PIDinew ∥ IDcs ∥ x ) ⊕ h(ru ∥ PIDinew ) D13 = h(PIDinew ∥ ru ∥PIDi ) ⊕ h(rs ⊕ rcs) D14 = h(SKcs ∥ D12 ∥ D13 ∥ h (IDi ∥ x ) ) M3 = {D9 , D10 , D11 , D12, D13 , D14} Pass M3 to Sj
Control Server

14. Proposed scheme (11/13) Authentication
Sj (ru ⊕ rcs) = D10 ⊕ h(PSIDjnew ∥ rs ∥ PSIDj ) SKs = h (rs ⊕ ru ⊕ rcs) check D11 ?= h(SKs ∥ D9 ∥ D10 ∥ B2) B1new = D9 ⊕ h(rs ∥ PSIDjnew ) (B1 , PSIDj) = (B1new , PSIDjnew) M4 = {D12, D13, D14} Pass M4 to Ui
Server

15. Proposed scheme (12/13) Authentication
Ui (rs ⊕ rcs) = D13 ⊕ h(PIDinew ∥ ru ∥ PIDi ) SKu = h (ru ⊕ rs ⊕ rcs) check D14 ?= h(SKu ∥ D12 ∥ D13 ∥ C2* ) C1new = D12 ⊕ h (ru ∥ PIDinew) ⊕ HPi (C1 , PIDi ) = (C1new , PIDinew )
User

16. Proposed scheme(13/13) Password change
Control Server
User
Ui send M5 to CS with password change request
M5 = M1
CS computes ru , IDi , PIDinew and check IDi , D4
If pass, calculates D12 and D15
D12 = h(PIDinew ∥ IDcs ∥ x ) ⊕ h(ru ∥ PIDinew )
D15 = h(IDi ∥ , PIDi ∥ PIDinew ∥ ru ∥ D12)
send M6 = {D12 , D15} to Ui
smart card check D15 ?= h(IDi ∥ PIDi ∥ PIDinew ∥ ru ∥ D12)
If so, Ui can input PWinew as a new password
computes HPinew = h(PWinew ∥ bi)
C1new = D12 ⊕ h(ru ∥ PIDinew) ⊕ HPinew
C2new = C2* ⊕ h(IDi ∥ HPinew)
C3new = bi ⊕ h(IDi ∥ PWinew)
replace (C1, C2, C3, PIDi ) with (C1new, C2new, C3new, PIDinew )

17. Experimental results(1/2)

18. Experimental results(2/2)
Th = the one-way hash function
TS = symmetric encryption/decryption algorithm
The execution time of XOR operations can be neglected when comparing to Th and TS

19. Conclusions
A new and robust authentication scheme for IoT-cloud architecture circumstances. An authentication scheme has high security and low cost.