1. 多媒體網路安全實驗室 A Strong User Authentication Framework for Cloud Computing Date ： 2012.08.10 Reporter : Hong Ji Wei Authors : Amlan Jyoti Choudhury, Mangal Sain, Pardeep Kumar Hoon Jae-Lee, Hyotaek Lim From : 2011 IEEE Asia -Pacific Services Computing Conference

2. 多媒體網路安全實驗室 OUTLINE INTRODUCTION AND MOTIVATION 1 LITERATURE REVIEW 2 CLOUD SECURITY ARCHITECTURE 33 CONCLUSION PROPOSED SCHEME 44 SECURITY ANALYSIS 3546 1

3. 多媒體網路安全實驗室 INTRODUCTION AND MOTIVATION  Cloud computing has evolved through a number of different services.  The basic goal of cloud computing is to provide great flexibility to users.  Users do not need to concern with the processing details.  Cloud systems are divided into three categories public cloud, private cloud and hybrid cloud. 2

4. 多媒體網路安全實驗室  The new cloud computing technology offers many advantages: 1. Information shared in virtual environment 2. Dynamic scalability 3. Storage utility 4. Software utilization 5. Platform and infrastructure utilization 6. Managed distributed computing power INTRODUCTION AND MOTIVATION 3

5. 多媒體網路安全實驗室 LITERATURE REVIEW TT 4

6. 多媒體網路安全實驗室 CLOUD SECURITY ARCHITECTURE 5 2 3 1 6 7 4 5 ID,PW Login Request One –time password Successful Authentication

7. 多媒體網路安全實驗室 PROPOSED SCHEME 6  The notations used in this paper are mentioned below in table.

8. 多媒體網路安全實驗室 PROPOSED SCHEME  The proposed scheme consists of three phases: 1. Registration 2. Login 3. Authentication  In addition, It also consists one activity called Password change. 7

9. 多媒體網路安全實驗室 PROPOSED SCHEME  Registration 8 ClientServer Secure Channel Enter x into smartcard

10. 多媒體網路安全實驗室 PROPOSED SCHEME  Login 9 ClientServer

11. 多媒體網路安全實驗室 PROPOSED SCHEME  Authentication 10 ClientServer

12. 多媒體網路安全實驗室 PROPOSED SCHEME  Password change ClientSmartcard 11

13. 多媒體網路安全實驗室 SECURITY ANALYSIS  Session key agreement: This key is different in every login session and cannot be replayed after the session expires.  Replay attack The onetime key is valid for one login session, and the key is delivered to the user via mobile out of band channel.  Password guessing attack The scheme uses complex password term (J=h(ID h(PW x))) using one way hash function. 12

14. 多媒體網路安全實驗室 SECURITY ANALYSIS  Stolen verifier attack and data modification attack Smartcard contain {I,J,B,p,g,h(.),x}, but without the knowledge of ID,PW and K it is very difficult to find B', L, R.  Insider attack The password is never used openly, instead, it is digest with (J=h(ID h(PW x))), which is very difficult to invert. 13

15. 多媒體網路安全實驗室 SECURITY ANALYSIS  Mutual authentication 14 ClientServer

16. 多媒體網路安全實驗室 SECURITY ANALYSIS  Man in the middle attack 15 ClientServer

17. 多媒體網路安全實驗室 CONCLUSION  This paper proposes a strong user authentication framework for cloud computing with many security features.  The proposed protocol can resist many popular attacks.  There are two strong factor signifies in this scheme 1. Something you know 2. Something you have 16

18. 多媒體網路安全實驗室