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From: Rusty Russell <rusty@rustcorp.com.au>
To: DING FENG <dingfeng12345@gmail.com>, Luke Dashjr <luke@dashjr.org>
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Date: Fri, 13 Jul 2018 09:34:14 +0930
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Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>,
	lightning-dev@lists.linuxfoundation.org
Subject: Re: [bitcoin-dev] [Lightning-dev]  BIP sighash_noinput
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DING FENG <dingfeng12345@gmail.com> writes:
> Hi,
>
> I'm a junior developer and a bitcoin user.
> And I have read this thread carefully.
>
> I'm very worried about "SIGHASH_NOINPUT".
>
> Because "SIGHASH_NOINPUT" looks will be widely used, and it makes reuse
> address more dangerous.

No.

A wallet should *never* create a SIGHASH_NOINPUT to spend its own UTXOs.
SIGHASH_NOINPUT is useful for smart contracts which have unique
conditions, such as a pair of peers rotating keys according to an agreed
schedule (eg. lightning).

Cheers,
Rusty.