[bitcoin-dev] Centralizing mining by force

Marc Bevand m.bevand at gmail.com
Wed Nov 8 05:04:07 UTC 2017

What you describe is an example of a majority attack ("51% attack"). No
technical mechanism in Bitcoin prevents this. However in practice, miners
are not incentivized to perform this attack as it would destroy confidence
in Bitcoin, and would ultimately impact their revenues.


On Mon, Nov 6, 2017, 22:32 Robert Taylor via bitcoin-dev <
bitcoin-dev at lists.linuxfoundation.org> wrote:

> Forgive me if this has been asked elsewhere before, but I am trying to
> understand a potential failure mode of Bitcoin mining.
> A majority of miners can decide which valid blocks extend the chain. But
> what would happen if a majority of miners, in the form of a cartel decided
> to validly orphan any blocks made by miners outside of their group? For
> example, they could soft fork a new rule where the block number is signed
> by set of keys known only to the cartel, and that signature placed in the
> coinbase. Miners outside of the cartel would not be able to extend the
> chain.
> It would be immediately obvious but still valid under the consensus rules.
> What are the disincentives for such behavior and what countermeasures could
> be done to stop it and ensure mining remained permissionless? I think this
> is a valid concern because while it may not be feasible for one actor to
> gain a majority of hash alone, it is certainly possible with collusion.
> Robert
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev at lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20171108/46545fe7/attachment.html>

More information about the bitcoin-dev mailing list