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From: Pavel Moravec <pavel.moravec@braiins.cz>
Date: Sat, 8 Apr 2017 08:33:01 +0000
Message-ID: <CACDYSUROutAMV7C8pUXz0PMvH5awkw-XUtce7BxTtZMD_yUm5A@mail.gmail.com>
To: Jimmy Song <jaejoon@gmail.com>, 
	Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
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Subject: Re: [bitcoin-dev] A Small Modification to Segwit
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> Second, we can make this change relatively quickly. Most of the Segwit te=
sting stays valid and this change can be deployed relatively quickly.

It is true only for nodes software. Most of the world's mining
infrastructure (at least for pool mining) is not ready for such
change. Current version of Stratum protocol doesn't support block
version changing. A broad adoption would require:

- A new standard extension to the mining protocol (generally, we want
the hash rate to be free to change the used pool without efficiency
loss)
- Pool operators must change their software.
- All miners must update their firmware IF they have compatible
hardware (we know there is compatible hardware out there but
definitely not all of the currently used). The firmware can be changed
after the mining protocol extension is settled.

Until all miners update (firmware or hardware), the change encourages
large difference in mining efficiency. And IMO it gives another
advantage to large mining operations in general.

> But think of it this way, if some newer ASIC optimization comes up, would=
 you rather have a non-ASICBoosted hash rate to defend with or an ASICBoost=
ed hash rate? Certainly, the latter, being higher will secure the Bitcoin n=
etwork better against newer optimizations.

You make a strong assumption that the new optimization is not
compatible with overt ASICBoost. If it is compatible, ASICBoost
doesn't help you with "defending against" the new optimization at all.
And it can be the case that the new optimization is based on ASICBoost
so you can make the situation "worse" by allowing it.

> Certainly, if only one company made use of the extra nonce space, they wo=
uld have an advantage.

Can you explain why the reality should be significantly different? In
sufficiently near future.

> Is that patented in any jurisdiction, all jurisdictions or only certain j=
urisdictions? Would a patent granted for SHA256 in Swaziland be sufficient =
for Bitcoin to change the Proof of Work algorithm?

We don't have to deal with any such theoretical situation now. You
proposal goes in opposite direction, by adding support for patented
algorithm. I don't know myself what the possible legal implications
are (maybe only for a subset of miners) so I consider it as an
unnecessary risk. At least before some conclusive legal analysis says
differently.