To: =?UTF-8?Q?Emin_G=c3=bcn_Sirer?= <el33th4x0r@gmail.com>,
	Bitcoin Dev <bitcoin-dev@lists.linuxfoundation.org>
References: <5b9ba6c4-6d8f-9c0b-2420-2be6c30f87b5@cannon-ciota.info>
	<CAPkFh0s-ZyLN06h+EpU2rfgs5TkTEPG+3FZyWSXusp-Z9XHasQ@mail.gmail.com>
From: CANNON <cannon@cannon-ciota.info>
Message-ID: <40cc105b-80ee-4848-0624-f4a8f1070173@cannon-ciota.info>
Date: Fri, 14 Apr 2017 02:22:18 +0000
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Subject: Re: [bitcoin-dev] Defending against empty or near empty blocks from
 malicious miner takeover?
Precedence: list

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On 03/24/2017 04:27 PM, Emin Gün Sirer wrote:
> Because there's no consensus on the contents of the mempool, this approach
> is unsafe and will lead to forks. It also opens a new attack vector where
> people can time the flood of new transactions with the discovery of a block
> by a competitor, to orphan the block and to fork the chain.
> 

I know this is a delayed reply.

Without intending to revive an older thread, my intentions are to clarify
what I have meant in my original post just in case anyone misinterprets 
where I said

"For example would be something like this:
If block = (empty OR  <%75 of mempool) THEN discard
This threshold just an example."

I should have clarified that with this idea blocks would not be rejected if 
does not match what that nodes have in their mempool, because as you have said,
there is no consensus on the contents of mempool and the mempool will vary from
node to node.

Instead what I have meant is that with this idea, nodes would only reject blocks if
they are empty or less than a determined percentage when compared to what is in mempool.

While this specific defense proposal I posted may or may not be a good idea, was only 
throwing this idea out there to create discussion on possible defenses against an empty
or near empty block attack.


- --
Cannon
PGP Fingerprint: 2BB5 15CD 66E7 4E28 45DC 6494 A5A2 2879 3F06 E832 
Email: cannon@cannon-ciota.info

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