From: Johnson Lau <jl2012@xbt•hk>
To: Eric Voskuil <eric@voskuil•org>
Cc: bitcoin-dev <bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] BIP30 and BIP34 interaction (was Re: [BIP Proposal] Buried Deployments)
Date: Fri, 18 Nov 2016 02:08:09 +0800 [thread overview]
Message-ID: <6F2B3EA2-4245-4A0E-8E19-12D02A871815@xbt.hk> (raw)
In-Reply-To: <59D27CC6-120C-4673-9F20-6B5E95EA60C6@voskuil.org>
The fact that some implementations ban an invalid block hash and some do not, suggests that it’s not a pure p2p protocol issue. A pure p2p split should be unified by a bridge node. However, a bridge node is not helpful in this case. Banning an invalid block hash is an implicit “first seen” consensus rule.
jl2012
> On 18 Nov 2016, at 01:49, Eric Voskuil <eric@voskuil•org> wrote:
>
> Actually both possibilities were specifically covered in my description. Sorry if it wasn't clear.
>
> If you create a new valid block out of an old one it's has potential to cause a reorg. The blocks that previously built on the original are still able to do so but presumably cannot build forever on the *new* block as it has a different tx. But other new blocks can. There is no chain split due to a different interpretation of valid, there are simply two valid competing chains.
>
> Note that this scenario requires not only block and tx validity with a tx hash collision, but also that the tx be valid within the block. Pretty far to reach to not even get a chain split, but it could produce a deep reorg with a very low chance of success. As I keep telling people, deep reorgs can happen, they are just unlikely, as is this scenario.
>
> If you create a new invalid block it is discarded by everyone. That does not invalidate the hash of that block. Permanent blocking as you describe it would be a p2p protocol design choice, having nothing to do with consensus. Libbitcoin for example does not ban invalidated hashes at all. It just discards the block and drops the peer.
>
> e
next prev parent reply other threads:[~2016-11-17 18:08 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-17 0:06 Jorge Timón
2016-11-17 0:10 ` Eric Voskuil
2016-11-17 0:31 ` Tier Nolan
2016-11-17 0:43 ` Eric Voskuil
2016-11-17 0:53 ` Eric Voskuil
2016-11-17 8:44 ` Peter Todd
2016-11-17 9:58 ` Eric Voskuil
2016-11-17 10:22 ` Tier Nolan
2016-11-17 11:22 ` Eric Voskuil
2016-11-17 11:38 ` Alex Morcos
2016-11-17 12:22 ` Eric Voskuil
2016-11-17 15:40 ` Johnson Lau
2016-11-17 17:01 ` Eric Voskuil
2016-11-17 17:22 ` Johnson Lau
2016-11-17 17:49 ` Eric Voskuil
2016-11-17 18:08 ` Johnson Lau [this message]
2016-11-18 3:20 ` Eric Voskuil
2016-11-18 14:43 ` Johnson Lau
2016-11-18 16:47 ` Eric Voskuil
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