Re: [bitcoin-dev] Introducing a POW through a soft-fork

[Eric Voskuil <eric@voskuil.org>]

[-- Attachment #1: Type: text/plain, Size: 2826 bytes --]

If a block that would be discarded under previous rules becomes accepted after a rule addition, there is no reason to not simply call the new rule a hard fork. IOW it's perfectly rational to consider a weaker block as "invalid" relative to the strong chain. As such I don't see any reason to qualify the term, it's a hard fork. But Peter's observation (the specific behavior) is ultimately what matters.

e

> On Nov 6, 2017, at 12:30, Paul Sztorc via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> wrote:
> 
> +1 to all of Peter Todd's comments
> 
>> On Nov 6, 2017 11:50 AM, "Peter Todd via bitcoin-dev" <bitcoin-dev@lists.linuxfoundation.org> wrote:
>> 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
>> 
>> _______________________________________________
>> bitcoin-dev mailing list
>> bitcoin-dev@lists.linuxfoundation.org
>> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>> 
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev

[-- Attachment #2: Type: text/html, Size: 4195 bytes --]