From: Matt Whitlock <bip@mattwhitlock.name>
To: Kevin Greene <kgreenek@gmail.com>
Date: Tue, 26 May 2015 00:56:28 -0400
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Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] Zero-Conf for Full Node Discovery
Precedence: list

Who would be performing a Sybil attack against themselves? We're talking about a LAN here. All the nodes would be under the control of the same entity. In that case, you actually want them all connecting solely to a central hub node on the LAN, and the hub node should connect to "diverse and unpredictable" other nodes on the Bitcoin network.


On Monday, 25 May 2015, at 9:46 pm, Kevin Greene wrote:
> This is something you actually don't want. In order to make it as difficult
> as possible for an attacker to perform a sybil attack, you want to choose a
> set of peers that is as diverse, and unpredictable as possible.
> 
> 
> On Mon, May 25, 2015 at 9:37 PM, Matt Whitlock <bip@mattwhitlock.name>
> wrote:
> 
> > This is very simple to do. Just ping the "all nodes" address (ff02::1) and
> > try connecting to TCP port 8333 of each node that responds. Shouldn't take
> > but more than a few milliseconds on any but the most densely populated LANs.
> >
> >
> > On Monday, 25 May 2015, at 11:06 pm, Jim Phillips wrote:
> > > Is there any work being done on using some kind of zero-conf service
> > > discovery protocol so that lightweight clients can find a full node on
> > the
> > > same LAN to peer with rather than having to tie up WAN bandwidth?
> > >
> > > I envision a future where lightweight devices within a home use SPV over
> > > WiFi to connect with a home server which in turn relays the transactions
> > > they create out to the larger and faster relays on the Internet.
> > >
> > > In a situation where there are hundreds or thousands of small SPV devices
> > > in a single home (if 21, Inc. is successful) monitoring the blockchain,
> > > this could result in lower traffic across the slow WAN connection.  And
> > > yes, I realize it could potentially take a LOT of these devices before
> > the
> > > total bandwidth is greater than downloading a full copy of the
> > blockchain,
> > > but there's other reasons to host your own full node -- trust being one.
> > >
> > > --
> > > *James G. Phillips IV*
> > > <https://plus.google.com/u/0/113107039501292625391/posts>
> > > <http://www.linkedin.com/in/ergophobe>
> > >
> > > *"Don't bunt. Aim out of the ball park. Aim for the company of
> > immortals."
> > > -- David Ogilvy*
> > >
> > >  *This message was created with 100% recycled electrons. Please think
> > twice
> > > before printing.*
> >
> >
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