Re: [saag] can an on-path attacker drop traffic?

Dan Harkins <dharkins@lounge.org> Sun, 04 October 2020 01:14 UTC

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Date: Sat, 03 Oct 2020 18:14:22 -0700
From: Dan Harkins <dharkins@lounge.org>
In-reply-to: <CABcZeBNuBhu8KUoZJsY3VR8LzDa78_n53rRZ-5nMrpCbqh_6KQ@mail.gmail.com>
To: Eric Rescorla <ekr@rtfm.com>, Fernando Gont <fernando@gont.com.ar>
Cc: Michael Richardson <mcr+ietf@sandelman.ca>, IETF SAAG <saag@ietf.org>
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Subject: Re: [saag] can an on-path attacker drop traffic?
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On 10/2/20 7:03 AM, Eric Rescorla wrote:
[snip]
>
> For capabilities, our basic assumption is what is often called a
> Dolev-Yao attacker, in which the attacker has complete control of the
> channel (this is what 3552 describes as the Internet Threat model
> [0]). However, it's also useful to try to consider more limited
> attackers such as those who can only read from the wire and those who
> cannot remove packets.
   Why? If we want to develop protocols that are secure in the presence of
a powerful attacker who has complete control of the medium what value
is there in considering a "more limited attacker"?

   It sounds like you're making a distinction between a passive attacker
and an active attacker. Which is fine but what use do you see in a protocol
that is secure against this "limited attacker" but not against the more
powerful attacker?

   Dan.