Subject: Re: Re: Re: Terminology

From: Mehmet Ersue <[email-masked]>
Date: Sat, 15 Dec 2001 20:37:35 +0100 (CET)

Dear all,

(I apologize for responding so late, but I am not online in SLC.)

John W Noerenberg II <[email-masked]> wrote:

JN>...
JN> 
JN>                                                            
/-------\
JN>                                                           //     
   \\
JN>                                                          |    MPC
     |
JN>                                                          |       
     |
JN>                       /-------\                           \\     
   //
JN>                     // location\\                         
/\-------/
JN>                    |   proxy     |                        /
JN>                    |             |                       /
JN>                     \\ LocSrv  //  +----------+         /
JN>      /----\           \---+---/    | Mobile   |        /
JN>    / App    \             |        | station  |       /     
//-----\\
JN>   |          |            |        |          |      /    |/     
   
\|
JN>   | LocReq   |---------------------| LocSrv   +-----/-----+   PDE
    
|
JN>    \        /                      |          |           |\     
   
/|
JN>      \----/                        +----+-----+            
\\-----//
JN>                                         |
JN>                                     +---+----+
JN>                                     |Local   |
JN>                                     |node    |
JN>                                     |        |
JN>                                     +--------+
JN> 
JN> 
JN>...

I agree with the terms:

Target (but I do not agree with the definition! see below)
Location Requestor (LocReq) (was called Client, Location Recipient 
location seeker)
Location Server (LocSrv)
Mobile Positioning Center (MPC)
Position Determination Engine (PDE)

I want to introduce one more:
Location Data Source (LocSrc) (which *could* be just the
 a combination of the Mobile Positioning Center (MPC), and the 
 Position Determination Engine (PDE), but it also could be something
 very different)

[email-masked] wrote:

BR> I think we all agree on the term "target"; it's the device
BR> that has a location.

I am not sure. If I have two devices, and I switch from one to the 
other,
I may be able to tell the location server that now I at this or that
location, even without telling which device I may be using.
In an extreme case, I can make a phone call to some trusted
location server and, using a certain password or whatever, I may tell
the server that now I am at this or that other place. My location 
information does not necessarily depend on some mechanical device
measuring the position of a target *device*. Perhaps I am just
entering
a pin code everytime I enter a new region of an airport or a
hospital.

For me, target is the entity whose location is desired by the 
Location Requestor (was: client).
         
BR> We usually use the term "user", in two contexts.  One is that
BR> the target is usually described as associated with the user.
BR> We really want the location of the user, but until we get
BR> implanted with GPS receivers and radios, we have targets
BR> that are separate from the user.  The other context we
BR> use "user" is that the user is the source of the privacy
BR> concern.  Ultimately, it is the user that grants rights to
BR> some other entity to learn the location of the target.

Do we need the "user" in the first sense? Of course,
locating the user may be different from locating a particular
target device that he carries (or not), but from the point
of view of a geopriv protocol, we are only interested in
locating a "target" which can be an IP device, a person,
a mountain, or whatever. The target is charachterized
by identities and credentials, independently of being
or not a device, a person or whatever.

Ajith Narayanan <[email-masked]> wrote:

A> The word "owner" is probably good, but I'd hope for a better word.
  
The
A> problem I see is this --  by calling this entity the "owner" we 
suggest
A> that he/she has some rightful ownership of the location sighting 
(where
A> location sighting = the information that a certain target is
sighted 
at a
A> certain location at a certain time).  When the "user" has the 
rightful
A> ownership of that information (i.e., owner == user) he/she is
likely 
to
A> have the best possible control of their privacy.  However, in some

settings
A> -- e.g., the cases where the "carrier" (e.g., a Voluntary Location
A> Processor) legally owns the location sighting information -- the 
user will
A> not have claim to such ownership, strictly speaking.  However, 
privacy may
A> still exist because of a contract between the "user" and the
"owner" 
(the
A> VLP carrier, in this case).  The carrier owns the information, but

may
A> allow the "user" to exercise control over its disclosure.  Thus
the 
user
A> exercises policy control over how the location sighting is used, 
without
A> having to be the owner of the information per se.   This is not
the 
best
A> scenario for privacy, but I think we need to be able to talk about

such
A> scenarios,  and refer to such a user who exercises control over 
location
A> disclosure policy.

Not exactly. At least when I proposed the word "owner" in my draft 
(draft-cuellar-geopriv-reqs-00.txt) I ment something different.
It is not the "owner of the location information" (if such thing 
exists), it is more like the owner of the policies that determine
what may be done with that information.

I quote from my draft:
      Owner of the target:
         An entity that has the authorization to decide the policies
         that apply to the location information of the target (for
         instance, equipment in the field). Most frequently, the
owner
         of the target is the target itself. One target may have 
several
         owners and one owner may have several targets. The owner is
in
         possession of credentials showing that he is owner of the
         identifier of the target.

(The last sentence is to mean that the owner is able to show the
proper
authorization credentials, created by consent of the target or the 
owner).

Thus the "carrier" in your example is not an owner.

If I understand you correctly, the point that you are making
is that not all Location Data Sources are owners of the target.
I agree on that. Quoting again from my draft:

         Also some network entity, properly authenticated and 
authorized
         by the network, may send the Location Information to the
         Location Server. This could be some location detection 
function
         in the access network. The authentication /authorization
         requirements for this case are for further discussion. This
         case is different from the owner of the target, since there
is
         no close relationship between this network entity and this
         particular target.

This means that this location data provider may not have been 
explicitely
authorized by the target (or an owner of the target) to provide the 
location
data. 

Let me explain why this kind of distinction is important:
If we allow unauthorized Location Data Sources, and we do not
take correct precautions, some "Location Data Source" may play
attacks on the target. For instance, it may claim that I have
been visiting a certain place I have not been at. The location
server just sends this information to my wife or to my boss and 
I am in deep trouble.

This entity is close to what John Morris calls the "carrier" or the
untrusted involuntary location processor (ILP), but it is different.
The point, for me at least is not abstract "trust" (like the one
inherited from the fact the entity is in my access network), or
voluntary or not, the point is authorization.

Best regards,

Jorge

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