[bitcoin-dev] Hypothetical 2 MB hardfork to follow BIP148

Jared Lee Richardson jaredr26 at gmail.com
Fri Jun 2 19:40:36 UTC 2017


> Maybe there's some hole in Jorge's logic and scrapping blockmaxsize has quadratic hashing risks, and maybe James' 10KB is too ambitious; but even if so, a simple 1MB tx size limit would clearly do the trick.  The broader point is that quadratic hashing is not a compelling reason to keep blockmaxsize post-HF: does someone have a better one?

I think this is exactly the right direction to head.  There are
arguments to be made for various maximum sizes... Maybe the limit
could be set to 1mb initially, and at a distant future block
height(years?) automatically drop to 500kb or 100kb?  That would give
anyone with existing systems or pre-signed transactions several years
to adjust to the change.  Notification could (?possibly?) be done with
a non-default parameter that must be changed to continue to use 100kb
- <1mb transactions, so no one running modern software could claim
they were not informed when that future date hits.

I don't see any real advantages to continuing to support transactions
larger than 100kb excepting the need to update legacy use cases /
already signed transactions.

On Tue, May 30, 2017 at 8:07 PM, Jacob Eliosoff via bitcoin-dev
<bitcoin-dev at lists.linuxfoundation.org> wrote:
> Maybe there's some hole in Jorge's logic and scrapping blockmaxsize has
> quadratic hashing risks, and maybe James' 10KB is too ambitious; but even if
> so, a simple 1MB tx size limit would clearly do the trick.  The broader
> point is that quadratic hashing is not a compelling reason to keep
> blockmaxsize post-HF: does someone have a better one?
>
>
>
> On May 30, 2017 9:46 PM, "Jean-Paul Kogelman via bitcoin-dev"
> <bitcoin-dev at lists.linuxfoundation.org> wrote:
>>
>> That would invalidate any pre-signed transactions that are currently out
>> there. You can't just change the rules out from under people.
>>
>>
>> On May 30, 2017, at 4:50 PM, James MacWhyte via bitcoin-dev
>> <bitcoin-dev at lists.linuxfoundation.org> wrote:
>>
>>
>>>
>>>  The 1MB classic block size prevents quadratic hashing
>>> problems from being any worse than they are today.
>>>
>>
>> Add a transaction-size limit of, say, 10kb and the quadratic hashing
>> problem is a non-issue. Donezo.
>>
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