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From: Peter Todd <pete@petertodd.org>
To: Devrandom <c1.bitcoin@niftybox.net>,
	Bitcoin Protocol Discussion
	<bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] Introducing a POW through a soft-fork
Date: Mon, 6 Nov 2017 14:50:00 -0500	[thread overview]
Message-ID: <20171106195000.GA7245@fedora-23-dvm> (raw)
In-Reply-To: <CAB0O3SVjhG19R61B78hFCPwfwWemTXj=tOsvgAgoNbjFYXXAtg@mail.gmail.com>

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On Wed, Nov 01, 2017 at 05:48:27AM +0000, Devrandom via bitcoin-dev wrote:

Some quick thoughts...

> Hi all,
> 
> Feedback is welcome on the draft below.  In particular, I want to see if
> there is interest in further development of the idea and also interested in
> any attack vectors or undesirable dynamics.
> 
> (Formatted version available here:
> https://github.com/devrandom/btc-papers/blob/master/aux-pow.md )
> 
> # Soft-fork Introduction of a New POW

First of all, I don't think you can really call this a soft-fork; I'd call it a
"pseudo-soft-fork"

My reasoning being that after implementation, a chain with less total work than
the main chain - but more total SHA256^2 work than the main chain - might be
followed by non-supporting clients. It's got some properties of a soft-fork,
but it's security model is definitely different.

> ### Aux POW intermediate block
> 
> Auxiliary POW blocks are introduced between normal blocks - i.e. the chain
> alternates between the two POWs.
> Each aux-POW block points to the previous normal block and contains
> transactions just like a normal block.
> Each normal block points to the previous aux-POW block and must contain all
> transactions from the aux-POW block.

Note how you're basically proposing for the block interval to be decreased,
which has security implications due to increased orphan rates.

> ### Heaviest chain rule change
> 
> This is a semi-hard change, because non-upgraded nodes can get on the wrong
> chain in case of attack.  However,

Exactly! Not really a soft-fork.

-- 
https://petertodd.org 'peter'[:-1]@petertodd.org

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  parent reply	other threads:[~2017-11-06 19:50 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-01  5:48 [bitcoin-dev] Introducing a POW through a soft-fork Devrandom
2017-11-02 23:55 ` Tao Effect
2017-11-03  1:02   ` Devrandom
2017-11-06 19:50 ` Peter Todd [this message]
2017-11-06 20:30   ` Paul Sztorc
2017-11-06 20:55     ` Eric Voskuil
2017-11-07  4:38       ` Devrandom
2017-11-11 19:51         ` Eric Voskuil
2017-11-06 22:39   ` Devrandom
2017-11-06 23:38     ` Devrandom

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