From joseph at lightning.network  Fri Aug 12 21:20:34 2016
From: joseph at lightning.network (Joseph Poon)
Date: Fri, 12 Aug 2016 14:20:34 -0700
Subject: [Lightning-dev] Blinded channel observation
In-Reply-To: <87d1leodg7.fsf@rustcorp.com.au>
References: <CAGt-sprhFi39+PbP1A8rkfQRMW78JT=r5AF-UOu+xsf64Q4Mzg@mail.gmail.com>
	<87a8gmpkde.fsf@rustcorp.com.au>
	<20160809192814.GA22477@lightning.network>
	<877fbpps8s.fsf@rustcorp.com.au>
	<20160809222938.GA25606@lightning.network>
	<87wpjpnzwd.fsf@rustcorp.com.au>
	<20160811041626.GA8114@lightning.network>
	<87d1leodg7.fsf@rustcorp.com.au>
Message-ID: <20160812212034.GA29612@lightning.network>

Hi Rusty,

Yeah, interesting thoughts!

On Fri, Aug 12, 2016 at 01:17:52PM +0930, Rusty Russell wrote:
> I still don't understand why use an HMAC-of-tx instead of just the txid?
> What does it gain?

I'm presuming you need to index by txid to see if there needs to be a
penalty transaction broadcast, so you can't use that as a secret key.

-- 
Joseph Poon