Subject: Re: [bitcoin-dev] Hash of UTXO set as consensus-critical

From: Justus Ranvier <[email-masked]>
Date: Mon, 21 Sep 2015 12:15:12 -0500

On 19/09/15 15:11, Rune K. Svendsen wrote:
> An honest miner is a miner that supports the network by building on top of the best valid chain. A malicious miner is one who wants to disrupt the Bitcoin network, not support it, for example by executing a 51% attack which mines empty blocks on top of the best chain.

This isn't a particularly good definition.

"An honest miner is a miner that supports the network by building on top
of the best valid chain."

What is the "best valid chain"? The one with the most proof of work? The
one that meets some other definition of "best"?

"A malicious miner is one who wants to disrupt the Bitcoin network, not
support it"

This is a tautology, the equivalent of saying "a malicious miner is a
miner that is malicious" A true, but entirely useless, statement.

"for example by executing a 51% attack which mines empty blocks on top
of the best chain."

Again, you're begging the question with the word "attack", because
that's what you're supposed to demonstrate.

Apparently the difference between honest mining and malicious mining is
empty blocks? You've said in both cases the miners are extending the
"best valid chain". Is extending the best valid chain with an empty
block always a malicious act?

What's the significance of 51% in this definition? Is the same empty
block which extended the best valid chain honest if the miner who
produced it has 49% of the network hashing power and malicious if they
add a few more ASIC units?

-- 
Justus Ranvier
Open Bitcoin Privacy Project
http://www.openbitcoinprivacyproject.org/
[email-masked]
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