On 10/7/14, 9:35 AM, "Joseph Lorenzo Hall" <[email protected]> wrote:

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>As the showrunner for the confidentiality effort in the IAB privacy
>and security program, please do share your feedback with us.


Great document Š some observations on a missing topic area:


The draft-iab-privsec-confidentiality-threat-00 provides a good
overview of many issues, but does not mention the problems associated
with static MAC addresses. MAC addresses, while perhaps considered
beneath the purview of IETF have a significant impact on the system
considerations for private Internet communications.

MAC addresses are assigned to device interfaces to support
link level communications on subnets.  These addresses are assigned
through a global registry with allocations to individual companies to
distribute unique assignments.  Being unique, the MAC addresses are
often used as a device identification.  Some operating systems use
a device MAC address to create a GUID (globally unique identifier)
that is then used to identify the host.  The GUID is then embedded
in documents to identify the source platform.

MAC addresses are used to create IPv6 addresses.  The unique MAC address
provides a convenient  mechanisms to assign a unique IP address.
This convenience for unique IPv6 assignment makes a unique
MAC address an integral part of many emerging architectures
(e.g for IoT). Binding the device unique MAC address to an IPv6
address makes the communicating device identifiable by
any observer end-to-end.

Static MAC addresses are a particularly serious problem in
wireless networks.  Simply sniffing of traffic provides
the device unique address which is readily correlated
to the specific user.

IEEE 802 does provide facilities for local MAC addresses.  The
local MAC addresses are not used widely and have been applied
primarily for special purpose protocol applications
(e.g. Local MAC used as BSSID for IBSS).  The local MAC
addresses does allow a random address to be used for the link
provides significant improvements for privacy, but the
impact on bridging, routing and device authentication need
to be considered.  Frequently changing MAC addresses will
Potentially overflow routing tables.  DHCP servers may run
out of available addresses.  Guidelines for protocols that
use MAC addresses will need to be developed to prevent
disruption of network communications.  Some IETF protocols
may need to be modified to facilitate the use of local
MAC addresses.




>We are
>also contemplating a companion document on mitigations for the threats
>outlined in the threat model.

Š  if we want to build a private Internet
we should ensure that we have a solid foundation at the
bottom of the stack (MAC addresses).  Addressing architectures
must be be reconsidered to ensure that a static address is not
necessary.  Identity should not be an addresses, but some other
non-assigned locally generated identifier that can be bound
to a end device cryptographically.

Paul



>
>best, Joe
>
>On 9/15/14, 10:56 AM, Stephen Farrell wrote:
>> 
>> Hi all,
>> 
>> Richard and a few folks started work on documenting a problem
>> statement [1] some time ago. As I think was stated here before it
>> seems like a good plan for that to be progressed as part of the
>> IAB's re-factored security/privacy programme. So Brian Trammell has
>> picked up the pen and pushed out [2].
>> 
>> Comments very welcome (I've still to read it myself so will send my
>> comments here too when I've had a chance),
>> 
>> Cheers, S.
>> 
>> 
>> [1] http://tools.ietf.org/html/draft-barnes-pervasive-problem [2]
>> https://tools.ietf.org/html/draft-iab-privsec-confidentiality-threat
>>
>>  _______________________________________________ perpass mailing
>> list [email protected]
>> https://www.ietf.org/mailman/listinfo/perpass
>> 
>
>- -- 
>Joseph Lorenzo Hall
>Chief Technologist
>Center for Democracy & Technology
>1634 I ST NW STE 1100
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