Date: Wed, 5 Apr 2017 22:31:23 -0400
From: Peter Todd <pete@petertodd.org>
To: Gregory Maxwell <greg@xiph.org>,
	Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Message-ID: <20170406023123.GA1071@savin.petertodd.org>
References: <CAAS2fgR84898xD0nyq7ykJnB7qkdoCJYnFg6z5WZEUu0+-=mMA@mail.gmail.com>
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User-Agent: Mutt/1.5.23 (2014-03-12)
Subject: Re: [bitcoin-dev] BIP proposal: Inhibiting a covert attack on the
 Bitcoin POW function
Precedence: list


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On Wed, Apr 05, 2017 at 09:37:45PM +0000, Gregory Maxwell via bitcoin-dev w=
rote:
> On that basis, I offer the following BIP draft for discussion.
> This proposal does not prevent the attack in general, but only
> inhibits covert forms of it which are incompatible with
> improvements to the Bitcoin protocol.
>=20
> I hope that even those of us who would strongly prefer that
> ASICBOOST be blocked completely can come together to support
> a protective measure that separates concerns by inhibiting
> the covert use of it that potentially blocks protocol improvements.

While I'm in favour of blocking covert usage of ASICBOOST, there's every re=
ason
to block non-covert usage of it as well. In a low margin business like mini=
ng,
the advatange it gives is enormous - quite possibly 10x your profit margin -
and given that barrier free access to being able to purchase ASICs is alrea=
dy
an archilles heal for Bitcoin there is every reason to eliminate this legal
vulnerability. Additionally, it's a technical vulnerability as well: we want
getting into the ASIC manufacturing and design business to have as low barr=
iers
to entry as is feasible, and the ASICBOOST exploit significantly increases =
the
minimum capital requirements to do so.

Remember that the whole purpose of PoW is to destroy value on a level playi=
ng
field. Anything that inhibits a level playing field is an exploit. While th=
is
isn't standard crypto - we can't fix every exploit completely - since we're
going to do a technical change to partially mitigate the ASCIBOOST exploit
there is every reason to fully mitigate it.

--=20
https://petertodd.org 'peter'[:-1]@petertodd.org

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