後卓越計畫 進度報告 楊舜仁老師實驗室

3GPP-WLAN Interworking (collaboration with ICL/ITRI)

WLAN Authentication Message Flow (1) WLAN UE WLAN AN 3GPP AAA Server HSS/HLRWAG probe response association request association response probe request open system authentication response open system authentication request

WLAN UE WLAN AN 3GPP AAA Server HSS/ HLR WAG 7. EAP Request /Identity 8. EAP Response /Identity NAI based temp identifier or IMSI 9. EAP Response /Identity NAI based temp identifier or IMSI 10. AV retrieval 11. Multimedia Auth Answer AV(1….n) WLAN Authentication Message Flow (2)

WLAN UE WLAN AN 3GPP AAA Server HSS/ HLR WAG 12. EAP Request /SIM- Start [AT_VERSION_LIST] 13. EAP Request /SIM- Start [AT_VERSION_LIST] 14. EAP Response / SIM-Start [AT_NONCE_MT, AT_SELECTED_VERSI ON ] 15. EAP Response / SIM-Start [AT_NONCE_MT, AT_SELECTED_VERSI ON ] 16. EAP Request /SIM- challenge [AT_RAND AT_MAC] 17. EAP Request /SIM- challenge [AT_RAND AT_MAC] WLAN Authentication Message Flow (3)

WLAN UE WLAN AN 3GPP AAA Server HSS/ HLR WAG Verifies AT_MAC 21. EAP Success [keying material] 20. Policy enforcement delivery 22. EAP Success Peer runs GSM algorithms, verifies AT_MAC and derives session keys 18. EAP Response /SIM- challenge[AT_MAC] 19. EAP Response /SIM- challenge[AT_MAC] WLAN Authentication Message Flow (4)

PDG A uthentication Scenario

IMS Authentication MSSGSNHSS/AuCCSCF PDP Context Activation Register (impi) Multimedia Auth Request (impi) Multimedia Auth Answer AV(1….n) Select authentication vector AV 401 Unauthorized (RAND || AUTN) Register (RES) Compare RES and XRES 200 OK Server Assignment Request Server Assignment Answer

Message flow of EAP-SIM (briefly) ClientServer EAP/identity EAP/SIM-start EAP/SIM-challenge EAP/Success(failure) Server EAP/identity EAP/SIM-start EAP/SIM-challenge EAP/Success(failure) Client OriginalOur scheme

Our Proposed Scheme on PDG Scenario (1) StationTTGGGSNAAA srvHLR/ HSS 1.IKE_SA_INIT [Hdr, SA,D_H value, Nonces] 2.IKE_AUTH Request [Hdr, IDi(user ID),IDr(W-APN), CP, SAi2, TSi, TSr] 3.EAP-Resp/Identity [User ID, W-APN 4.Check user’s subscription on if tunnel is allowed User profile and AVs retrieval if needed 5.EAP-Req/SIM-Start 6.IKE_AUTH Request [Hdr, IDr(PDG ID), Cert, AUTH, EAP-Req/SIM-Start] 7.IKE_AUTH Response [Hdr,EAP-Resp/SIM-Challenge] 8.EAP-Resp/SIM-Challenge 9.EAP-Success + keying material 10.AUTH payload is computed using the keying material (MSK) 11.IKE_AUTH Response [Hdr,EAP-Success ] 12.IKE_AUTH Request [Hdr,AUTH]

StationTTGGGSNAAA srvHLR/ HSS 13 Check the correctness of AUTH payload 14.Create PDP Context request 15.Create PDP Context response 16.IKE_AUTH Response [Hdr, AUTH, CP, SAr2, TSi, TSr] Our Proposed Scheme on PDG Scenario (2)

IMS Authentication Reduction MSSGSN HSS/AuC CSCF PDP Context Activation Store the (imsi,impi) pair Check if IMSI HSS (impi)=imsi 200 OK (Impi rand) (impi,imsi, rand) (Impi, rand) (IMSI HSS (impi), User profile,CK, IK) Retrieve the IMSI value Select a rand and compute CK=f3 k (rand) IK=f4 k (rand) Compute CK=f3 k (rand) IK=f4 k (rand)