To: Aymeric Vitte <vitteaymeric@gmail.com>,
	Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
References: <5b9ba6c4-6d8f-9c0b-2420-2be6c30f87b5@cannon-ciota.info>
	<35ba77db-f95a-4517-c960-8ad42a633ba0@gmail.com>
From: CANNON <cannon@cannon-ciota.info>
Message-ID: <f4849cef-3c40-31a4-e323-6a731bb52bc2@cannon-ciota.info>
Date: Sat, 25 Mar 2017 16:12:54 +0000
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Subject: Re: [bitcoin-dev] Defending against empty or near empty blocks from
 malicious miner takeover?
Precedence: list

On 03/24/2017 07:00 PM, Aymeric Vitte wrote:
> I don't know what "Time is running short I fear" stands for and when 50%
> is supposed to be reached

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On 03/24/2017 07:00 PM, Aymeric Vitte wrote: > I don't know what
"Time is running short I fear" stands for and when 50% > is supposed
to be reached

According to current hashrate distribution tracking site coin.dance,
very likely within less than four weeks according to current hashrate
takeover rate.

While a fork is very likely, that I dont really fear because worst
case scenario is that bitcoin still survives and the invalid chain
becomes an alt.  My fear is the centralized mining power being used
to attack the valid chain with intentions on killing it. [1]

Shouldn't this 50% attack they are threatening be a concern? If it
is a concern, what options are on the table. If it is not a concern
please enlightent me as to why.


[1] Source:
https://www.reddit.com/r/Bitcoin/comments/6172s3/peter_rizun_tells_miners_to_force_a_hard_fork_by/

Text:

The attack quoted from his article:
https://medium.com/@peter_r/on-the-emerging-consensus-regarding-bitcoins-block-size-limit-insights-from-my-visit-with-2348878a16d8

    [Level 2] Anti-split protection  Miners will orphan the
    blocks of non-compliant miners prior to the first larger block
    to serve as a reminder to upgrade. Simply due to the possibility
    of having blocks orphaned, all miners would be motivated to
    begin signalling for larger blocks once support definitively
    passes 51%. If some miners hold out (e.g., they may not be
    paying attention regarding the upgrade), then they will begin
    to pay attention after losing approximately $15,000 of revenue
    due to an orphaned block.

    [Level 3] Anti-split protection  In the scenario where Levels
    1 and 2 protection fails to entice all non-compliant miners to
    upgrade, a small-block minority chain may emerge. To address the
    risk of coins being spent on this chain (replay risk), majority
    miners will deploy hash power as needed to ensure the minority
    chain includes only empty blocks after the forking point. This
    can easily be accomplished if the majority miners maintain a
    secret chain of empty blocks  built off their last empty
    block  publishing only as much of this chain as necessary
    to orphan any non-empty blocks produced on the minority chain.


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