Subject: RE: how much privacy do we need? (was Re: Advantages and disadvantages of using CB64 type of identifiers

From: "Christian Huitema" <[email-masked]>
Date: Fri, 9 Jul 2004 09:42:01 -0700

> So, i agree with Erik that there are three roles that an app can play:
> - Server
> - Client
> - p2p participant

We have to be careful when using this terminology. The definition of
server, for example, has two common meanings. For the general public, a
server is some machine that seats in a computer center and provides a
set of services. In many protocol definitions, the server is the party
in the communication that accepts a TCP connection. Obviously, the
privacy requirements are derived from the first definition, not the
second one, and we should make that very clear.

-- Christian Huitema

---

From: "Christian Huitema" <[email-masked]>
Date: Fri, 9 Jul 2004 10:01:07 -0700

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On
> Behalf Of Erik Nordmark
> Sent: Friday, July 09, 2004 8:58 AM
> To: Brian E Carpenter
> Cc: Multi6 List
> Subject: Re: how much privacy do we need? (was Re: Advantages and
> disadvantages of using CB64 type of identifiers
> 
> > I'm not sure we have consensus that we even have a privacy goal,
> > except maybe the "do no harm" property compared to RFC 3041.
> 
> FWIW draft-ietf-multi6-multihoming-threats tries to capture that
> level, with some additional words about the current state of
> IP address privacy in IPv4 and IPv6.

The draft states:

   Today when a site is multihomed to multiple ISPs the common setup is
   that a single IP address prefix is used with all the ISPs.  As a
   result it is possible to track that it is the same host that is
   communication via all ISPs.

This is correct, but incomplete. When a *host* is multi-homed to several
ISP, e.g. through a GPRS connection and a wireless hot spot, the host is
provided with different IP addresses on each interface. I know that
multi6 studies "site" multi-homing, but I also know that the various
wedge solutions can potentially be used for host multi-homing scenarios
as well, and I am worried about that.

We may also observe that a common practice in site multi-homing in IPv4
is to use some form of address translation, effectively hiding the
identity of the specific host within a site.

-- Christian Huitema