Subject: Re: [Bitcoin-development] Criminal complaints against "network disruption as a service" startups

From: Jan Møller <[email-masked]>
Date: Mon, 16 Mar 2015 09:44:33 +0100

What we were trying to achieve was determining the flow of funds between
countries by figuring out which country a transaction originates from.
To do that with a certain accuracy you need many nodes. We chose a class C
IP range as we knew that bitcoin core and others only connect to one node
in any class C IP range. We were not aware that breadwallet didn't follow
this practice. Breadwallet risked getting tar-pitted, but that was not our
intention and we are sorry about that.

Our nodes DID respond with valid blocks and merkle-blocks and allowed
everyone connecting to track the blockchain. We did however not relay
transactions. The 'service' bit in the version message is not meant for
telling whether or how the node relays transactions, it tells whether you
can ask for block headers only or full blocks.

Many implementations enforce non standard rules for handling transactions;
some nodes ignore transactions with address reuse, some nodes happily
forward double spends, and some nodes forward neither blocks not
transactions. We did blocks but not transactions.

In hindsight we should have done two things:
1. relay transactions
2. advertise address from 'foreign' nodes

Both would have fixed the problems that breadwallet experienced. My
understanding is that breadwallet now has the same 'class C' rule as
bitcoind, which would also fix it.

Getting back on the topic of this thread and whether it is illegal, your
guess is as good as mine. I don't think it is illegal to log incoming
connections and make statistical analysis on it. That would more or less
incriminate anyone who runs a web-server and looks into the access log.
At lease one Bitcoin service has been collecting IP addresses for years and
given them to anyone visiting their web-site (you know who) and I believe
that this practise is very wrong. We have no intention of giving IP
addresses away to anyone, but we believe that you are free to make
statistics on connection logs when nodes connect to you.

On a side note: When you make many connections to the network you see lots
of strange nodes and suspicious patterns. You can be certain that we were
not the only ones connected to many nodes.

My takeaway from this: If nodes that do not relay transactions is a problem
then there is stuff to fix.

/Jan

On Fri, Mar 13, 2015 at 10:48 PM, Mike Hearn <[email-masked]> wrote:

> That would be rather new and tricky legal territory.
>
> But even putting the legal issues to one side, there are definitional
> issues.
>
> For instance if the Chainalysis nodes started following the protocol specs
> better and became just regular nodes that happen to keep logs, would that
> still be a violation? If so, what about blockchain.info? It'd be shooting
> ourselves in the foot to try and forbid block explorers given how useful
> they are.
>
> If someone non-maliciously runs some nodes with debug logging turned on,
> and makes full system backups every night, and keeps those backups for
> years, are they in violation of whatever pseudo-law is involved?
>
> I think it's a bit early to think about these things right now. Michael
> Grønager and Jan Møller have been Bitcoin hackers for a long time. I'd be
> interested to know their thoughts on all of this.
>
>
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