So this is a bit of a side-issue maybe but I do wonder
if there's any functional/technical reason, other than
"the FCC said so," to identify a specific device in the
paws protocol with a long-lived identifier?
I can see why you'd want a device type of some sort,
and the DB might need some kind of session ID, but
I don't get the long-lived device identifier thing
at all as a functional requirement. Can anyone explain?
I'm not asking now from the privacy or security p-o-v,
but rather because its easier and cheaper and simpler to
not bother if you don't have to.
It does also interact with privacy & security of course.
Once you have to manage the identifier then you may need
to go to some trouble to protect that, but that's a
secondary question.
Thanks,
S.
On 02/03/2012 11:19 PM, Paul Lambert wrote:
using it themselves or retransmitting it. The resulting data one
whitespace availability will be visible to people and or devices which
are not completely controlled by the regulatory agencies.
As such, what is the role of confidentiality with regard to this
information?
All channel availability (at least for the FCC) is openly available. There is
no threat of disclosure of this information. It's actually the reverse. For
planning purposes to buy and use WS devices - you really would like a good
picture of available spectrum. It would be very detremental to market adoption
to limit access to the available channels.
That said - the current incumbants we discuss are just TV and microphones. In the
future, we might be sharing with public saftey or military applications that would not
want readily accessable maps of their locations disseminated. "Open" consumer
devices might in these scenarios see no spectrum and the approved devices would get
allocations. This still should be out-of-scope. These types of devices are not in our
use case scenarios.
Privacy as you point out alone is a good justification for some form of
confidentiality. But protecting a devices identity may not require encryption
of the full paws messages.
Intgrity and data origin authentication seem more important for the protocol
design considerations.
Paul
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of
Joel M. Halpern
Sent: Friday, February 03, 2012 11:51 AM
To: [email protected]
Cc: [email protected]
Subject: Re: [paws] Threat model (Rev 3)
Can we please include in this document some articulation of the
confidentiality assumption we are making with regard to the whitespace
data itself? I am not trying to object to the threats. (And the
personal information collection issues are enough to jsutify include
confidentiality mechanisms in the solutions.)
But I am still trying to get my head around this. There are going to be
hoards of whitespace devices. They will be getting the data, and either
using it themselves or retransmitting it. The resulting data one
whitespace availability will be visible to people and or devices which
are not completely controlled by the regulatory agencies.
As such, what is the role of confidentiality with regard to this
information?
Yours,
Joel
On 2/3/2012 2:34 PM, [email protected] wrote:
Below is Rev 3 of the threat model based on feedback from Stephen,
Nancy
and Gabor (Thanks).
-Raj
Rev 3 (3/2/12)
Threat model for the PAWS protocol
----------------------------------
Assumptions:
............
o It is assumed that an attacker has full access to the network medium
between the master device and the white space database. The
attacker
may be able to eavesdrop on any communications between these
entities. The link between the master device and the white space
database can be wired or wireless and provides IP connectivity.
o It is assumed that the master device or the white space database
have NOT been compromised from a security standpoint.
Threat 1: User modifies a device to masquerade as another valid
certified device
The master device needs to authenticate itself with the white
space database prior to requesting channel information. The
attacker may try to get access to the secrets of the master
device which can be used maliciously. The effect of such an
attack being successful would result in a malicious client
replaying the stolen authentication/authorization secrets to a
white space database.
Threat 2: Spoofed white space database
A master device discovers a white space database(s) thru which
it can query for channel information. The master device needs
to ensure that the white space database with which it
communicates with is an authentic entity. The white space
database needs to provide its identity to the master device
which can confirm the validity/authenticty of the database. An
attacker may attempt to spoof a white space database and
provide responses to a master device which are malicious and
result in the master device causing interference to the
primary
user of the spectrum.
Threat 3: Modifying a query request
An attacker may modify the query request sent by a master
device to a white space database. The attacker may change the
location of the device or the capabilities in terms of its
transmit power or antenna height etc. which could result in
the
database responding with incorrect information about available
channels or max transmit power allowed. The result of such an
attack is that the master device would cause intereference to
the primary user of the spectrum. It could also result in a
denial of service to the master device by indicating that no
channels are available.
Threat 4: Modifying a query response
An attacker could modify the query response sent by the white
space database to a master device. The channel information or
transmit power allowed type of parameters carried in the
response could be modified by the attacker resulting in the
master device using channels that are not available at a
location or transmitting at a greater power level than allowed
resulting in interference to the primary user of that
spectrum. Alternatively the attacker may indicate no channel
availability at a location resulting in a denial of service to
the master device.
Threat 5: Unauthorized use of channels by an uncertified device
An attacker may be a master device which is not certified for
use by the relevant regulatory body. The attacker may listen
to
the communication between a valid master device and white
space
database and utilize the information about available channels
in the response message by utilizing those channels. The
result
of such an attack is unauthorized use of channels by a master
device which is not certified to operate.
The master device querying the white space database may be
operated by a law-enforcement agency and the communications
between the device and the database are intended to be kept
private. A malicious device should not be able to eavesdrop on
such communications.
Threat 6: Third party tracking of white space device location and
identity
A white space database may require a master device to provide
its identity in addition to its location in the query request.
Such location/identity information can be gleaned by an
eavesdropper. A master device may prefer to keep the
location/identity information secret. Hence the protocol
should
provide a means to protect the location and identity
information of the master device and prevent tracking of
locations associated with a white space database. If
regulations do not require the identity of the master device
to
be provided to the white space database, the master is not
required to include its identity in the query.
Threat 7: Termination of device service for reasons other than
incumbent protection
A white space database may include a mechanism by which
service
and channels allocated to a master device can be revoked. A
malicious node can send a revoke message to a master
device. This results in denial of service to the master
device.
_______________________________________________
paws mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/paws
_______________________________________________
paws mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/paws
_______________________________________________
paws mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/paws
_______________________________________________
paws mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/paws
