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Date: Sun, 22 Dec 2013 19:22:46 -0800
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Subject: Re: [Bitcoin-development] Bitcoin difficulty sanity check suggestion
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-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Ryan, these sort of adjustments introduce security risks. If you were
isolated from the main chain by a low-hashpower attacker, how would
you know? They'd need just three days without you noticing that
network block generation has stalled - maybe they wait for a long
weekend - then after that the block rate is normal but completely
controlled by the attacker (and isolated from mainnet).

There are fast acting alternative difficulty adjustment algorithms
being explored by some alts, such as the 9-block interval, 144-block
window, Parks-McClellan FIR filter used by Freicoin to recover from
just such a mining bubble. If it were to happen to bitcoin, there
would be sophisticated alternative to turn to, and enough time to make
the change.

On 12/22/2013 07:10 PM, Ryan Carboni wrote:
> I think Bitcoin should have a sanity check: after three days if
> only four blocks have been mined, difficulty should be adjusted
> downwards.
> 
> This might become important in the near future. I project a
> Bitcoin mining bubble.
> 
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