From: Anthony Towns <aj@erisian•com.au>
To: "Jakob Rönnbäck" <jakob.ronnback@me•com>
Cc: Bitcoin Dev <bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] Adjusted difficulty depending on relative blocksize
Date: Fri, 14 Aug 2015 17:00:25 +0200 [thread overview]
Message-ID: <CAJS_LCVUJKUitR52AHGsJoBxt2ddOQJYpE=OQN62NzvenHLe=Q@mail.gmail.com> (raw)
In-Reply-To: <116B26BD-D8E8-4AFD-A619-2EAC348DA5E6@me.com>
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On 14 August 2015 at 16:48, Jakob Rönnbäck <
bitcoin-dev@lists•linuxfoundation.org> wrote:
> 14 aug 2015 kl. 16:20 skrev Anthony Towns <aj@erisian•com.au>:
>
> On 14 August 2015 at 11:59, Jakob Rönnbäck <
> bitcoin-dev@lists•linuxfoundation.org> wrote:
>
>> What if one were to adjust the difficulty (for individual blocks)
>> depending on the relative size to the average block size of the previous
>> difficulty period? (I apologize if i’m not using the correct terms, I’m not
>> a real programmer, and I’ve only recently started to subscribe to the
>> mailing list)
>>
>
> That would mean that as usage grew, blocksize could increase, but
> confirmation times would also increase (though presumably less than
> linearly). That seems like a loss?
>
> Would that really be the case though? If it takes 5% to find a block, but
> it contains 5% more transactions would that not mean it’s the same? That
> would argue against the change if not for the fact that the blocks will be
> bigger for the next difficulty period.
>
If you're waiting for one confirmation, something like that works -- you
might from 95% chance of 10 minutes 5% chance of 20 minutes to 100% chance
of 10m30s. But if you want 144 confirmations (eg) you go from 95% chance of
1 day, 5% chance of 1 day 10 minutes; to 100% chance of 1 day 72 minutes.
> If you also let the increase in confirmation time (due to miners finding
> harder blocks rather than a reduction in hashpower) then get reflected back
> as decreased difficulty, it'd probably be simpler to just dynamically
> adjust the max blocksize wouldn't it?
>
> I guess that could make the difficulty fluctuate a bit depending on the
> amount of transactions and the fees being paid. Would it really matter in
> the long run though? Since it’s the same amount of miners, doesn’t that
> just mean it’s just the number that is lower, not the actual investment
> needed to mine the blocks? Not sure if this would open up some forms of
> attacks on the system for someone willing to lose money though…
>
Once blocksizes had normalised as much larger than 1MB with a corresponding
higher average hashrate, a bad actor could easily mine a raft of valid
empty/small blocks at the minimum hash rate and force a reorg (and do
doublespends, etc).
Cheers,
aj
--
Anthony Towns <aj@erisian•com.au>
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next prev parent reply other threads:[~2015-08-14 15:00 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-14 9:59 Jakob Rönnbäck
2015-08-14 13:32 ` Angel Leon
2015-08-14 14:19 ` Jakob Rönnbäck
2015-08-14 16:37 ` [bitcoin-dev] libconsensus assertion fails if used in multiple threads Tamas Blummer
2015-08-14 21:10 ` Cory Fields
2015-08-18 5:03 ` Cory Fields
2015-08-18 10:31 ` Tamas Blummer
2015-08-18 17:25 ` Cory Fields
2015-08-18 17:50 ` Cory Fields
2015-08-18 21:40 ` Eric Voskuil
2015-08-14 14:20 ` [bitcoin-dev] Adjusted difficulty depending on relative blocksize Anthony Towns
[not found] ` <A6B32C22-4006-434E-9B89-D7C99B5743A8@me.com>
2015-08-14 14:48 ` Jakob Rönnbäck
2015-08-14 15:00 ` Anthony Towns [this message]
2015-08-14 15:03 ` Adam Back
2015-08-14 15:14 ` Jakob Rönnbäck
2015-09-09 3:27 ` Tom Harding
2015-09-09 18:59 ` Warren Togami Jr.
2015-09-09 19:53 ` Tom Harding
2015-08-14 22:12 ` Tom Harding
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