From: "Jorge Timón" <jtimon@jtimon•cc>
To: Eric Lombrozo <elombrozo@gmail•com>
Cc: Bitcoin Dev <bitcoin-dev@lists•linuxfoundation.org>, nbvfour@gmail•com
Subject: Re: [bitcoin-dev] We need to fix the block withholding attack
Date: Sat, 26 Dec 2015 19:01:59 +0100 [thread overview]
Message-ID: <CABm2gDrkvsShE1Vbc9KVTTeFzjJJJrGj605pRxoOAWMwpMWn1w@mail.gmail.com> (raw)
In-Reply-To: <EC9193E8-DEC6-413F-A9AC-903E26E51824@gmail.com>
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The hashpower is a function of the block reward (subsidy + fees): it's
economically irrational to have costs greater than the reward (better just
turn off your miners) and in a perfect competition (a theoretical model)
profits tend to zero. That is, the costs tend to equal revenue (block
reward).
On Dec 26, 2015 6:38 PM, "Eric Lombrozo" <elombrozo@gmail•com> wrote:
> For simplicity, assume total network hashpower is constant. Also, assume
> the soft fork activates at the beginning of a retarget period.
>
> At the moment the soft fork activates, the effective difficulty is
> increased (by adding a second independent PoW check that must also be
> satisfied) which means more hashes on average (and proportionally more
> time) are required to find a block. At the end of the retarget period, the
> difficulty is lowered so that if the second PoW difficulty were to be kept
> constant the block interval would again average 10 mins.
>
> If we were to keep the second PoW difficulty constant, we would restore
> the same total PoW-to-time-unit ratio and the retarget difficulty would
> stabilize again so each block would once more require the same number of
> hashes (and same amount of time) on average as before.
>
> But we don't keep the second PoW difficulty constant - we increase it so
> once again more hashes on average are required to find a block by the same
> proportion as before. And we keep doing this.
>
> Now, the assumption that hashpower is constant is obviously unrealistic.
> If this is your bone of contention, then yes, I agree my model is overly
> simplistic.
>
> My larger point was to explore the extent of what's possible with only a
> soft fork - and we can actually go pretty far and even compensate for these
> economic shifts by increasing block size and rewards. The whole thing is
> clearly a huge mess - and I wouldn't recommend actually doing it.
>
>
>
> On December 26, 2015 7:33:53 AM PST, "Jorge Timón" <jtimon@jtimon•cc>
> wrote:
>>
>>
>> On Dec 26, 2015 9:24 AM, "Eric Lombrozo via bitcoin-dev" <
>> bitcoin-dev@lists•linuxfoundation.org> wrote:
>>
>> > Unfortunately, this also means longer confirmation times, lower
>> throughput, and lower miner revenue. Note, however, that confirmations
>> would (on average) represent more PoW, so fewer confirmations would be
>> required to achieve the same level of security.
>> >
>>
>> I'm not sure I understand this. If mining revenue per unit of time drops,
>> total pow per unit of time should also drop. Even if the inter-block time
>> is increased, it's not clear to me that the pow per block would necessarily
>> be higher.
>> What am I missing?
>>
>
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next prev parent reply other threads:[~2015-12-26 18:02 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-19 18:42 Peter Todd
2015-12-19 19:30 ` Bob McElrath
2015-12-19 20:03 ` jl2012
2015-12-20 3:34 ` Chris Priest
2015-12-20 3:36 ` Matt Corallo
2015-12-20 3:43 ` Chris Priest
2015-12-20 4:44 ` Peter Todd
2015-12-26 8:12 ` Multipool Admin
2015-12-27 4:10 ` Geir Harald Hansen
2015-12-28 19:12 ` Peter Todd
2015-12-28 19:30 ` Emin Gün Sirer
2015-12-28 19:35 ` Multipool Admin
2015-12-28 19:33 ` Multipool Admin
2015-12-28 20:26 ` Ivan Brightly
2015-12-29 18:59 ` Dave Scotese
2015-12-29 19:08 ` Jonathan Toomim
2015-12-29 19:25 ` Allen Piscitello
2015-12-29 21:51 ` Dave Scotese
2015-12-20 3:40 ` jl2012
2015-12-20 3:47 ` Chris Priest
2015-12-20 4:24 ` jl2012
2015-12-20 5:12 ` Emin Gün Sirer
2015-12-20 7:39 ` Chris Priest
2015-12-20 7:56 ` Emin Gün Sirer
2015-12-20 8:30 ` Natanael
2015-12-20 11:38 ` Tier Nolan
2015-12-20 12:42 ` Natanael
2015-12-20 15:30 ` Tier Nolan
2015-12-20 13:28 ` Peter Todd
2015-12-20 17:00 ` Emin Gün Sirer
2015-12-21 11:39 ` Jannes Faber
2015-12-25 11:15 ` Ittay
2015-12-25 12:00 ` Jonathan Toomim
2015-12-25 12:02 ` benevolent
2015-12-25 16:11 ` Jannes Faber
2015-12-26 0:38 ` Geir Harald Hansen
2015-12-28 20:02 ` Peter Todd
2015-12-26 8:23 ` Eric Lombrozo
2015-12-26 8:26 ` Eric Lombrozo
2015-12-26 15:33 ` Jorge Timón
2015-12-26 17:38 ` Eric Lombrozo
2015-12-26 18:01 ` Jorge Timón [this message]
2015-12-26 16:09 ` Tier Nolan
2015-12-26 18:30 ` Eric Lombrozo
2015-12-26 19:34 ` Jorge Timón
2015-12-26 21:22 ` Jonathan Toomim
2015-12-27 4:33 ` Emin Gün Sirer
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