Date: Tue, 15 Oct 2019 15:50:29 +0000
To: Braydon Fuller <braydon@purse.io>
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Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] Chain width expansion
Precedence: list


> > > > [...] to generate much longer chain with superslow timestamp increa=
se (~5 blocks in 1 second) without increasing difficulty (i.e. staying at m=
in. diff.). [...]
> > > > In that case, it would take about 7 minutes of block time seconds f=
or
> > > > the next retarget period, every 2016 blocks, and the difficulty wou=
ld
> > > > adjust. The difficulty would adjust in that case as if 2 weeks of b=
locks
> > > > had been mined in 7 minutes. For the difficulty to remain the same =
the
> > > > time between blocks needs to be 10 minutes.
> > > > This calculation does not apply under time warp attack. You can fak=
e timestamps of all blocks except for those relevant to the retarget calcul=
ation. Those are only the first and the last block in the 2016 block window=
.
>
> This must be in reference to the non-overlapping difficulty calculation
> and off-by-one bug?

Indeed.