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From: Eric Voskuil <eric@voskuil.org>
To: Peter Todd <pete@petertodd.org>
Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] BIP 151
Date: Tue, 28 Jun 2016 22:29:54 +0200	[thread overview]
Message-ID: <4DCF7DD2-6533-4F79-8CA1-871B67C01BDA@voskuil.org> (raw)
In-Reply-To: <20160628201447.GA1148@fedora-21-dvm>



> On Jun 28, 2016, at 10:14 PM, Peter Todd <pete@petertodd.org> wrote:
> 
>> On Tue, Jun 28, 2016 at 08:35:26PM +0200, Eric Voskuil wrote:
>> Hi Peter,
>> 
>> What in this BIP makes a MITM attack easier (or easy) to detect, or increases the probability of one being detected?
> 
> BIP151 gives users the tools to detect a MITM attack.
> 
> It's kinda like PGP in that way: lots of PGP users don't properly check keys,

PGP requires a secure side channel for transmission of public keys. How does one "check" a key of an anonymous peer? I know you well enough to know you wouldn't trust a PGP key received over an insecure channel.

All you can prove is that you are talking to a peer and that communications in the session remain with that peer. The peer can be the attacker. As Jonas has acknowledged, authentication is required to actually guard against MITM attacks.

> so an attacker won't have a hard time MITM attacking those users. But some
> users do check keys, a labor intensive manual process, but not a process that
> requires any real cryptographic sophistication, let alone writing any code.
> It's very difficult for widescale attackers to distinguish the users who do
> check keys from the ones that don't, so if you MITM attack _any_ user you run
> the risk of running into one of the few that does check, and those users can
> alert everyone else.
> 
> The key thing, is we need to get everyones communications encrypted first: if
> we don't the MITM attacker can intercept 99% of the communications with 0% risk
> of detection, because the non-sophisticated users are trivially distinguishable from the sophisticated users: just find the users with unencrypted
> communications!
> 
> -- 
> https://petertodd.org 'peter'[:-1]@petertodd.org


  reply	other threads:[~2016-06-28 20:29 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-28  2:31 [bitcoin-dev] BIP 151 use of HMAC_SHA512 Rusty Russell
2016-06-28  7:17 ` [bitcoin-dev] BIP 151 Eric Voskuil
2016-06-28  8:26   ` Jonas Schnelli
2016-06-28 16:45     ` Eric Voskuil
2016-06-28 18:22       ` Peter Todd
2016-06-28 18:35         ` Eric Voskuil
2016-06-28 20:14           ` Peter Todd
2016-06-28 20:29             ` Eric Voskuil [this message]
2016-06-28 20:36               ` Peter Todd
2016-06-28 21:22                 ` Eric Voskuil
2016-06-28 21:36                   ` Gregory Maxwell
2016-06-28 21:40                     ` Cameron Garnham
2016-06-28 22:07                       ` Eric Voskuil
2016-06-28 22:33                         ` Cameron Garnham
2016-06-28 23:29                           ` Eric Voskuil
2016-06-29  0:06                             ` Nick ODell
2016-06-28 21:59                     ` Eric Voskuil
     [not found]                       ` <CAAS2fgQ0Ocs8hF+pf+fWfkKKhQwxNKpY=JHpb_bwua7neVO8tg@mail.gmail.com>
2016-06-28 23:34                         ` Eric Voskuil
2016-06-28 20:06       ` Jonas Schnelli
2016-06-28 23:31         ` Eric Voskuil
2016-06-29 11:17       ` Alfie John
2016-06-30 11:56         ` Eric Voskuil
2016-06-30 12:20           ` Jonas Schnelli
2016-06-30 12:27             ` Eric Voskuil
2016-06-30 12:43               ` Jonas Schnelli
2016-06-30 15:22                 ` Eric Voskuil
2016-06-30 16:52                   ` Peter Todd
2016-06-30 18:25                     ` Eric Voskuil
2016-06-30 19:06                       ` Peter Todd
2016-06-30 20:26                         ` Eric Voskuil
2016-06-28 19:55     ` Gregory Maxwell
2016-06-28 23:33       ` Eric Voskuil
2016-06-29  1:01         ` Gregory Maxwell
2016-06-30  9:57           ` Eric Voskuil
2016-06-30 13:03             ` Pieter Wuille
2016-06-30 15:10               ` Eric Voskuil
2016-08-31 14:29                 ` Pieter Wuille
2016-06-30 13:36             ` Erik Aronesty
2016-06-30 14:47               ` Alfie John
2016-07-02  9:44               ` Chris Priest
2016-06-28 12:13   ` Jonas Schnelli
2016-06-28 17:39     ` Eric Voskuil
2016-06-28  7:19 ` [bitcoin-dev] BIP 151 use of HMAC_SHA512 Jonas Schnelli
2016-06-28  8:31   ` Arthur Chen
2016-06-29 18:34     ` Jonas Schnelli
2016-06-29 20:13       ` Peter Todd
2016-06-29 20:31         ` Jonas Schnelli
2016-06-29  1:00   ` Rusty Russell
2016-06-29  1:38     ` Arthur Chen
2016-06-29  1:56     ` Ethan Heilman
2016-06-29  6:58       ` Pieter Wuille
2016-06-29 14:38         ` Ethan Heilman
2016-06-29 18:46           ` Jonas Schnelli
2016-07-01  3:25       ` Rusty Russell
2016-07-01 22:42         ` Zooko Wilcox
2016-07-04  1:23           ` Arthur Chen
2016-07-04  1:44             ` Arthur Chen
2016-07-04  6:47               ` Jonas Schnelli
2016-07-04  6:37           ` Jonas Schnelli

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