1. 21-13-0172-01-MuGM IEEE 802.21 MEDIA INDEPENDENT HANDOVER DCN: 21-13-172-01-MuGM Title: Flowchart on VerifyGroupKey and a note on SAID Date Submitted: September, 17, 2013 Presented at IEEE 802.21 session #58 in Nanjing Authors or Source(s): Yoshikazu Hanatani (Toshiba) Abstract: This contribution provides flowcharts of a generating method and a verification method of VerifyGroupKey, and a note on SAID.

2. 21-13-0172-01-MuGM IEEE 802.21 presentation release statements This document has been prepared to assist the IEEE 802.21 Working Group. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEEs name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEEs sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.21. The contributor is familiar with IEEE patent policy, as outlined in Section 6.3 of the IEEE-SA Standards Board Operations Manual and in Understanding Patent Issues During IEEE Standards Development http://standards.ieee.org/board/pat/guide.html> Section 6.3 of the IEEE-SA Standards Board Operations Manualhttp://standards.ieee.org/guides/opman/sect6.html#6.3 http://standards.ieee.org/board/pat/guide.html IEEE 802.21 presentation release statements This document has been prepared to assist the IEEE 802.21 Working Group. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEEs name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEEs sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.21. The contributor is familiar with IEEE patent policy, as stated in Section 6 of the IEEE-SA Standards Board bylaws and in Understanding Patent Issues During IEEE Standards Development http://standards.ieee.org/board/pat/faq.pdf> Section 6 of the IEEE-SA Standards Board bylawshttp://standards.ieee.org/guides/bylaws/sect6-7.html#6 http://standards.ieee.org/board/pat/faq.pdf

3. Verify Group Key Purpose: VerifyGroupKey provides a verifiability for MGK. Each MN which obtained a MGK from a GroupKeyData can verify that all other MNs also obtain the same MGK from the GroupKeyData. VerifyGroupKey prevents a malicious Group Manager and a GroupKeyData with error. Change the name VerifyGroupKey toGroupKeyVerificationCode. VerifyGroupKey is a confusing name. 21-13-0172-01-MuGM

4. GKB-Enc A Set of Device Keys MGK GroupKeyData CompleteSubtree GroupKeyVerificatio nCode_Gen Key_Hierachy MIGKCK MIGEK GroupKeyVerificationCode AES-CMAC Block diagram: GroupKeyVerificationCode Verification Fixed String (Ex. 0x0123456789ABCDEF) 21-13-0172-01-MuGM

5. GKB-Dec A Device Key MGK GroupKeyData CompleteSubtree GroupKeyVerificatio nCode_Verif Key_Hierachy MIGKCK MIGEK GroupKeyVerificationCode Block diagram: GroupKeyVerificationCode Verification True/False Fixed String (Ex. 0x0123456789ABCDEF) 21-13-0172-01-MuGM

6. Flowchart: GroupKeyVerificationCode Generation Start GroupKeyVerificationCode Generation Read following parameters MGK Fixed string (0x0123456789ABCDEF) Derive MIGKCK from MGK using the key hierachy. (See 9.4.3) End GroupKeyVerificationCode := AES-CMAC-128(MIGKCK; 0x0123456789ABCDEF)

7. 21-13-0172-01-MuGM Flowchart: GroupKeyVerificationCode Verification Start GroupKeyVerificationCode Verification Read following parameters MGK GroupKeyVerificationCode Fixed string (0x0123456789ABCDEF) End Output a result of GroupKeyVerificationCode == AES-CMAC-128(MIGKCK; 0x0123456789ABCDEF) Derive MIGKCK from MGK using the key hierachy. (See 9.4.3)

8. On SAID MIHF of PoS can arbitrary decide a SAID for GKB-generated SA. A tuple of Source MIHF Identifier, SAID Group Identifier (Destination MIHF Identifier) and SAID in a message protected by GKB-generated SA shall be unique. A recommended deciding method of the SAID. Assign a group key version for a group ID as the Optional Data. 21-13-0172-01-MuGM