Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [TG4b Security subgroup status] Date Submitted: [16 November, 2004] Source: [Robert Cragie] Company [Jennic Ltd.] Address [Furnival Street, Sheffield, S1 4QT, UK] Voice:[+44 114 281 4512], FAX: [+44 114 281 2951], EMail:[rcc@jennic.com] Re: [Response to the call for proposal of IEEE 802.15.4b, MAC Enhancement] [If this is a response to a Call for Contributions, cite the name and date of the Call for Contributions to which this document responds, as well as the relevant item number in the Call for Contributions.] [Note: Contributions that are not responsive to this section of the template, and contributions which do not address the topic under which they are submitted, may be refused or consigned to the “General Contributions” area.] Abstract: [Discussion for several potential enhancements for current IEEE 802.15.4 MAC] Purpose: [For the discussion at IEEE 802.15.4b Study Group] Notice: This document has been prepared to assist the IEEE P802.15. 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. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. NOTE: Update all red fields replacing with your information; they are required. This is a manual update in appropriate fields. All Blue fields are informational and are to be deleted. Black stays. After updating delete this box/paragraph. Robert Cragie, Jennic Ltd.

2. TG4b security subgroup status Robert Cragie Jennic Limited Robert Cragie, Jennic Ltd.

3. Forward • This document summarises the discussion of the security subgroup in its teleconferences • The subgroup comprises: • Rene Struik (Certicom) (chair) • Jonathan Avey (Ember) • Jon Beniston (CompXs) • Robert Cragie (Jennic) • The original text was submitted by Robert Cragie via e-mail on 12th November 2004 • Comments were received only from Rene Struik Robert Cragie, Jennic Ltd.

4. Introduction • Document 15-04-0539-00 has been submitted • Contains many wide-ranging changes to the security specification in 802.15.4-2003 • Replaces section 7.6 and the PIB attributes. It also mandates the use of CCM* as specified in 15-04-0537-00 Robert Cragie, Jennic Ltd.

5. Backwards compatibility • The proposal is not backwards-compatible with the existing 802.15.4-2003 specification, e.g.: • The frame formats aredifferent (changes to the MHR) • The use of counters is different • CCM* is only backwards-compatible with CCM • The PAR does allow for security updates Robert Cragie, Jennic Ltd.

6. Ways forward • Swallow the pill and overhaul security and develop 15-04-0539 to be the replacement text • Swallow part of the pill and make carefully judged changes to security • Address the security issues in the comments database only • The security subgroup is currently digesting 15-04-0539-00 to see how big the pill is and what is in the pill. Robert Cragie, Jennic Ltd.

7. Outstanding contentious issues • Endianness of the frame counter field in the PDU • Whether counter fields were included in the authentication data Robert Cragie, Jennic Ltd.

8. Endianness • There has been no accepted solution yet but we have all agreed that we aregenerally agnostic to whatever is proposed. Robert Cragie, Jennic Ltd.

9. Authentication of counter field • This is still unclear in 15-04-0539-00. • On the teleconference on 14th October 2004, it was agreed that the counter fields should be authenticated. Robert Cragie, Jennic Ltd.

10. Specific discussion items • The chair of the subgroup, Rene Struik suggested three specific discussion items: • Compressed frame counter • Broadcast security • Multicast • These originate from document 02/474r2 Robert Cragie, Jennic Ltd.

11. Compressed frame counter • A compression technique for reducing the size of the PDU. • Additional cryptographic benefits as it is harderto do a denial-of-service attack via a counter rollover • There was an original proposal that this would be done on-the-fly and resynchronising uncompressed counters would be done automatically on failing to receive an acknowledgement but this was considered to pose too many complications on possible hardware implementations. • Therefore it was agreed that it would be handled manually and not based on the acknowledgements • Rene proposes that this is discussed further in San Antonio Robert Cragie, Jennic Ltd.

12. Broadcast security • No discussion has taken place yet • Rene proposes that this is discussed further in San Antonio Robert Cragie, Jennic Ltd.

13. Multicast • No discussion has taken place yet • Rene proposes that this is discussed further in San Antonio Robert Cragie, Jennic Ltd.