[schmichael]

> The more miner, the more secure

This isn't totally accurate. You need a lot of different miners and a high hash rate for security. The least secure place bitcoin can be is when a single miner controls most of the hash rate.

[riprowan]

This is exactly correct. All the hashpower in the world provides zero security if 51%+ of it is not "honest".

http://bitcoin.org/bitcoin.pdf

[arnauddri]

You're perfectly right, thanks for clarifying!

[hasch]

good point, but a mining monopoly would destroy the value and hence it's in the self-interest of miners to be diversified. that's an economical self-correcting mechanism on top of this technical mining/reward feedback mechanism.

[schmichael]

AFAIK this is the conventional wisdom but not a proven fact. A smart 51% attacker could profit and go unnoticed:

> And contrary to commonly-repeated assertions, a monopolist can engage in subtle attacks that are hard to detect.

http://hackingdistributed.com/2014/06/16/how-a-mining-monopo...