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Date: Wed, 06 Nov 2013 18:35:34 -0500
From: Matt Corallo <bitcoin-list@bluematt.me>
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Cc: bitcoin-development@lists.sourceforge.net
Subject: Re: [Bitcoin-development] [ANN] High-speed Bitcoin Relay Network
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No, the transactions relayed are piped through a bitcoind first (ie
fully verified by a bitcoind). For blocks, for which the timing needs to
be tighter, bitcoinj does SPV-validation. Though it is possible to
create a block which passes SPV validation but causes a DoS score, doing
so would cost a miner a full block's worth of profits, which they are
fairly unlikely to do. In any case, if it every becomes a problem, its
not hard to adapt addnode to allow higher DoS scores for individual nodes.

Matt

On 11/06/13 07:25, Tier Nolan wrote:
> 
> 
> 
> On Wed, Nov 6, 2013 at 5:50 AM, Matt Corallo <bitcoin-list@bluematt.me
> <mailto:bitcoin-list@bluematt.me>> wrote:
> 
>     Relay node details:
>      * The relay nodes do some data verification to prevent DoS, but in
>     order to keep relay fast, they do not fully verify the data they are
>     relaying, thus YOU SHOULD NEVER mine a block building on top of a
>     relayed block without fully checking it with your own bitcoin validator
>     (as you would any other block relayed from the P2P network).
> 
> 
> Wouldn't this cause disconnects due to misbehavior? 
> 
> A standard node connecting to a relay node would receive
> blocks/transactions that are not valid in some way and then disconnect.
> 
> Have you looked though the official client to find what things are
> considered signs that a peer is hostile?  I assume things like double
> spending checks count as misbehavior and can't be quickly checked by a
> relay node.
> 
> Maybe another bit could be assigned in the services field as "relay". 
> This means that the node doesn't do any checking. 
> 
> Connects to relay nodes could be command line/config file only.  Peers
> wouldn't connect to them.