An Enhanced Two-factor User Authentication Scheme in Wireless Sensor Networks

1. An Enhanced Two-factor UserAuthentication Scheme inWireless Sensor Networks DAOJING HE,YI GAO, SAMMY CHAN, CHUN CHEN ,JIAJUN BU Ad Hoc & Sensor Wireless Networks2010 Vol. 0, pp. 1–11 Citation:14 Presenter: 林致良 Date: 2013/4/22

2. Outline • Introduction • Related work • The new proposed protocol • Security and performance analysis • Conclusion

3. Outline • Introduction • Related work • The new proposed protocol • Security and performance analysis • Conclusion

4. Introduction • In WSNs, both Gateway (GW) nodes and external parties (users) are able to access directly the real-time data from the sensor nodes. • A two-factor authentication is a concept used to describe an authentication mechanism, where more than one factor is required to authenticate the communicating party.

5. Introduction

6. Introduction This paper points out: • Security weaknesses in Das M.’s schemesuch as suffering from insider attack. This paper presents : • An enhanced two-factor user authentication protocol.

7. Outline • Introduction • Related work • The new proposed protocol • Security and performance analysis • Conclusion

8. Related work Das M.'s scheme consists of two phases:  1. Registration phase 2. Authentication phase (1) Login phase (2) Verification Phase

9. Das M.'s scheme Registration phase Select , [ ,] (secure channel) symmetric key: K one-way hash function: h(⋅) User() GW node Compute Smart card {, h(), h(⋅), }

10. Related work Das M.'s scheme consists of two phases:  1. Registration phase 2. Authentication phase (1) Login phase (2) Verification Phase • This phase is invoked when Userwants to perform some queries to or accessdata from the network.

11. Das M.'s scheme Login phase Input , smart card validates with the stored ones in it. Smart card {, h(), h(⋅), } User() GW node T : current timestamp :dynamic login identity of Compute: Compute:

12. Verification Phase User() GW node (T*−T)≤ΔT Compute:

13. Verification Phase GW node :nearest sensor node Compute: =

14. Attack on Das M.'s scheme Registration phase Select , [ ,] (secure channel) • A privileged insider of the GW-node can obtain a user the message < ,>. • The insider can impersonate the user touse it to impersonate to access other GW-nodes. User() GW node

15. Design weakness on Das M.'s scheme • The GW-node, as a registration and access center, should know the real identities of all users in the authentication phase. • Although can be obtained by computing = ⊕h , the GW-node cannot get the real identity of any user because no password/verifier table is kept.

16. Outline • Introduction • Related work • The new proposed protocol • Security and performance analysis • Conclusion

17. The new proposed protocol The proposed scheme consists of three phases: 1. Registration phase 2. Authentication phase (1) Login phase (2) Verification Phase 3. Password updating phase

18. The new proposed protocol Registration phase Select ,,b [, h(b ⊕)] (secure channel) arbitrary number: b (large) secret number: K, J User() GW node Compute h(b ⊕) Compute: Smart card {, h(⋅), }

19. The new proposed protocol Login phase Input , smart card validates with the stored ones in it. Smart card {, h(⋅) , } User() GW node Compute: T : current timestamp :dynamic login identity of

20. Verification Phase User() GW node (T*−T)≤ΔT Compute:

21. Verification Phase GW node :nearest sensor node Compute: =

22. Password updating phase Smart card {, h(⋅) , } Input , smart card validates with the stored ones in it. User() Compute:

23. Outline • Introduction • Related work • The new proposed protocol • Security and performance analysis • Conclusion

24. Security Analysis The scheme can withstand the insider attack and the impersonation attack: registers to the GW-node by presenting h(b⊕) instead of the insider of the GW-node cannot directly obtain The scheme can obtain an user’s real identity: TheGW-node obtains the users real identity by computing = ⊕h(T||).

25. Performance Analysis : the delay time for the communication between a user and the GW-node. : the delay time for the communication between a GW-node and a sensor node. : the delay time for the communication between and a sensor node and a user. Note: XOR operation requires very few computations, thus its computation cost is neglected here.

26. Outline • Introduction • Related work • The new proposed protocol • Security and performance analysis • Conclusion

27. Conclusion • This paper points out the security weaknesses in a two-factor user authentication protocol for wireless sensor networks. • The analysis has shown that the security issues in that scheme can be solved in a very simple way, which is the proposal in this paper.