Re: Address privacy

[Tom Herbert <[e-mail]>]

On Tue, Jan 28, 2020 at 8:51 AM Nick Hilliard <[e-mail]> wrote:
>
> Tom Herbert wrote on 28/01/2020 03:10:
> > Yes, that's the "always on" network application that would allow
> > address tracking and identification at even high frequency of address
> > change. An exploit based on that is described in section 4.4 of
> > draft-herbert-ipv6-prefix-address-privacy-00. I believe the only way
> > to defeat this exploit would be single use (per flow), uncorrelated
> > address.
>
> persistent identification for apps (browser / mobile / etc) is handled
> using a variety of mechanisms, primarily client fingerprinting.  The
> best known example of client fingerprinting would be application
> cookies.  IP addressing information is only one input source and
> probably one of the less important ones because of the poor correlation
> between ip addresses and end users (e.g. large 1:n nats), and ip address
> changes (office to train wifi, to in-car cellular to home broadband, to
> coffee shop, etc).

Nick,

The problem isn't in identification for apps, it's that the fact that
the logs created by the app correlate user identity with an IP
address. Given that correlation, the log could conceivably be used to
identify participants in completely unrelated communications. Using IP
addresses to identify individuals involved in communications does
happen, there are a number of instances noted on the web particularly
in law enforcement.

Tom

>
> Overall privacy addresses fall into the category of things that seemed
> like a good idea at the time but in retrospect their usefulness fell
> away as people worked out other, more accurate ways to track end users
> and end user devices.
>
> Nick
>