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From: Christian Decker <decker.christian@gmail.com>
To: Anthony Towns <aj@erisian.com.au>,
Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>,
Pieter Wuille <pieter.wuille@gmail.com>,
Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
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<20181120202904.gmbg5ebegvsgqfys@erisian.com.au>
Date: Wed, 21 Nov 2018 12:20:44 +0100
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Subject: Re: [bitcoin-dev] Safer sighashes and more granular SIGHASH_NOINPUT
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Anthony Towns via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org>
writes:
> Given this implementation, NOINPUT effectively implies ANYONECANPAY,
> I think. (I think that is also true of BIP 118's NOINPUT spec)
I mentioned this in my reply to Pieter, but this may not be true if we
remove the blanking of the `hashSequence` field. Anyonecanpay would
allow changing the number of inputs in an arbitrary fashion, while
`noinput` without the blanking would (in a weird roundabout way) still
commit to the number of inputs. Maybe we want to make that more explicit
by also hashing the number of inputs? But I can't think of a good
usecase for keeping that, with noinput.
Cheers,
Christian
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