1 / 17

Further Security Enhancement for Optimal Strong-Password Authentication Protocol

Further Security Enhancement for Optimal Strong-Password Authentication Protocol. Tzung-Her Chen, Gwoboa Horng, Wei-Bin Lee ,Kuang-Long Lin 3/27/2004. Outline. Introduction Review of Ku-Chen scheme

yvon
Télécharger la présentation

Further Security Enhancement for Optimal Strong-Password Authentication Protocol

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Further Security Enhancement for Optimal Strong-Password Authentication Protocol Tzung-Her Chen, Gwoboa Horng, Wei-Bin Lee ,Kuang-Long Lin 3/27/2004

  2. Outline • Introduction • Review of Ku-Chen scheme • The problem of Ku-Chen scheme • The proposed scheme • Security Analysis • Conclusions

  3. Introduction • In 2000, Sandirigama et al. proposed SAS scheme lowered storage, processing, and transmission overheads. • In 2001, Lin, Sun, and Hwang proposed an enhanced password authentication scheme, called the OSPA.

  4. Introduction • In 2002,OSPA protocol has been shown vulnerable to the stolen-verifier attack and the impersonation attack. • In 2003, Ku and Chen proposed a new improved version for the OSPA protocol • In this paper, an improved scheme with mutual authentication is proposed.

  5. Review of Ku-Chen scheme • Notation: h(.) : collision-resistant hash function T : login times k : long-term secret key  :exclusive-or operation

  6. Review of Ku-Chen scheme • Registration phase • Authentication phase

  7. Chooses his identity ID and password PW and computes h2(PW 1) ID, h2(PW 1) Calculates verifier v1=h2(PW 1)h(ID k) Store {ID, v1,T=1} into the verification table

  8. ID, service request Find i from verification table by the ID T=i c1=h(PW i)h2(PW i) c2=h2(PW (i +1))h(PW i) c3=h(h3(PW(i +1))T)

  9. c1,c2,c3 Check c1, c2 Get h2(PWi) by vi h(ID k) y1=c1h2(PWi)=h(PW i) y2=c2y1=h2(PW(i+1)) Check if h(y1)=h2(PWi) h(h(y2) T)=c3 vi+1=h2(PW(i +1))h(IDk) Store ID ,T=i+1, and vi+1

  10. The problem of Ku-Chen scheme • The user is authenticated by the remote server. • But, remote server is not authenticated by the user (Server impersonation attack ).

  11. The proposed scheme • Registration phase • Authentication phase

  12. ID, h2(PW 1) Chooses his identity ID and password PW and computes h2(PW 1) Calculates verifier v1=h2(PW 1)  h(ID k) Store {ID, v1} into the verification table

  13. choose r randomly and compute r h2(PW i) Get h2(PW i) by vi  h(ID k) ID, r h2(PW  i) r =(r h2(PW  i)) h2(PW  i) h(r)h2(PW  i) Check r c1=h(PW i)h2(PW i) c2=h2(PW(i +1)) h(PW i) c3=h(h3(PW(i +1))T)

  14. c1,c2,c3 Check c1, c2 y1=c1h2(PWi)=h(PW i) y2=c2y1=h2(PW(i +1)) Check if h(y1)=h2(PW i) h(h(y2)T)=c3 vi+1=h2(PW(i +1))h(IDk) Store ID and vi+1

  15. Security Analysis • Password guess attack • Impersonation attack • Stolen-verifier attack • Server impersonation attack

  16. Conclusions • We point out the possible server impersonation problem in the Ku-Chen scheme and propose an enhanced version. • The proposed concept of security enhancement is also suitable for the other SAS-like schemes.

  17. THE END

More Related