Re: [alto] Eric Rescorla's Discuss on draft-ietf-alto-multi-cost-08: (with DISCUSS)

["Mirja Kuehlewind (IETF)" <[e-mail]>]

Hi Ekr,

I think the threat below can easily mitigated by not using multi-query because that’s a client side decisions. It’s probably good to anyway document the risk described below so clients are aware of it and can make an informed decision to use multi-query or not. Can you maybe proposed 2-3 sentences to be added to address your discuss?

Thanks,
Mirja


> Am 12.04.2017 um 01:02 schrieb Eric Rescorla <[e-mail]>:
> 
> Eric Rescorla has entered the following ballot position for
> draft-ietf-alto-multi-cost-08: Discuss
> 
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> 
> ----------------------------------------------------------------------
> DISCUSS:
> ----------------------------------------------------------------------
> 
> This document states:
> "This document does not introduce any privacy or security issues not
>   already present in the ALTO protocol."
> 
> This may be true, but it's not obvious it is, because when questions are
> asked together, that's more of a privacy signature than independently.
> So, suppose that application A asks for metric A and application B asks
> for metric B and application C asks for A and B. If these applications
> are mixed behind a CGN, with single queries then you don't know whether
> you have some A clients and some B clients, but if you do multi-query,
> it's clear these are C clients. This is a potentially serious issue if
> (for instance) Bittorrent always asks for a very distinguished set of
> parameters, so an ALTO server might use this to find Bittorrent clients.
> 
> 
> 
>