Re: [Pearg] About hiding in crowds

[Christian Huitema <[e-mail]>]

Sorry about the 404. I messed up with the GitHub project, and did not
realized it was set as "private". Fixed now. If you want to work on an
Internet draft, I am happy to collaborate.

-- Christian Huitema

On 8/13/2020 3:59 PM, Shivan Sahib wrote:
> Thanks for the note Christian. I remember that a similar point was
> brought up in the /"What can you learn from an IP?" /paper presented
> by Nikita Borisov at ANRW 2019 last
> year: https://dl.acm.org/doi/10.1145/3340301.3341133, video of
> presentation: https://youtu.be/pEnT2BJvyv0?t=106 
> In the discussion after, it was brought up that IPv6 could make things
> better (more to choose from, so less stickyness if servers wanted) or
> worse (less incentive to have the same IP address for multiple
> services). There was also some discussion around what
>
>   * the CDNs can do 
>   * the websites can do, and
>   * clients can do
>
> Sara and I were chatting today and we reckoned this was an
> architectural consideration (with research input) for Internet
> privacy. It seemed to us that a first step might be to write up the
> concern and possible solutions in an Internet Draft. 
>
> Thanks also for the blog post
> <https://huitema.wordpress.com/2020/08/09/can-internet-services-hide-in-crowds/>;
> I tried checking out https://github.com/private-octopus/centraldns but
> got a 404. 
>
> On Mon, Aug 10, 2020 at 4:25 PM Christian Huitema <[e-mail]
> <mailto:[e-mail]>> wrote:
>
>     A lot of the privacy extensions recently developed amount to
>     "hiding in
>     crowds". For example, SNI encryption assumes that multiple servers are
>     accessible through the same IP address. If the SNI is hidden, outside
>     observers won't know which one was accessed. DNS encryption makes the
>     same assumption in an indirect way. It assumes that we gain privacy by
>     hiding the DNS exchange that maps www.example.com
>     <http://www.example.com> to an IP address. This
>     is fine, except for the fact that most servers have their own IP
>     address. You can hide the DNS exchange, you can hide the SNI, but
>     outside observers will still be able to understand which servers
>     you are
>     accessing by simply looking at the address header. If we want real
>     privacy, we will need something else!
>
>     How do I know? I started with the Majestic Million list of domain
>     names,
>     and resolved 25,000 of these names, and found out that on average a
>     given IP address was shared by about 1.21 names, as explained in:
>     https://huitema.wordpress.com/2020/08/09/can-internet-services-hide-in-crowds/).
>     And then I resolved the next 25000 names to be more sure of the
>     results.
>     The average increased slightly, from 1.21 to 1.22, which does not
>     change
>     the results much. 74.6% of domains use an address that is unique to
>     them, 8.7% use an address shared by 2 domains, and only 8% use an
>     address shared by 10 or more servers. DNS encryption and SNI
>     encryption
>     do bring privacy for a minority of connection, for which it may
>     well be
>     important. But they do not improve privacy in 75% of the cases.
>
>     I understand that privacy-warriors can use VPN, proxies or Tor. But
>     these tools are far from perfect -- see the recent Sybil attacks
>     against
>     Tor, or the outveiling of shady business practices by many VPNs.
>     In any
>     case, these tools at best provide "privacy for a few active
>     users". But
>     that leaves aside the bulk of Internet users. Thus my question for
>     this
>     program: how would we provide privacy for the masses?
>
>     -- Christian Huitema
>
>
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