bitcoin attack on ghash ddosThe Bitcoin community has been in a full state of outrage recently as the Bitcoin mining pool crossed the 51% estimated hashrate distribution share. This sparked a fierce debate over mining centralization and the principle of a decentralized currency which has spilled over to the mainstream media with Bloomberg and Business Insider declaring that the worst fears have come to pass.


Peter Todd, a core bitcoin developer, announced that he would be selling 50% of his bitcoins, citing concerns over mining centralization and justifying his public announcement by stating that a non-public sale might amount to insider trading.

Emin Gün Sirer, a hacker and professor at Cornell University with more than 25 years experience in distributed systems and other computer science fields, recently called for a full on Hard Fork arguing that the 51% share gained by is indeed really Armageddon because “GHash is in a position to exercise complete control over which transactions appear on the blockchain and which miners reap mining rewards.” He suggests that coding changes to the protocol must be made so as to fully disincentivize pool mining.

Even Gavin Andresen, the Chief Scientist at the Bitcoin Foundation, has joined the ongoing uproar with a public post titled “Centralized Mining” which many found to be lacking as it did not provide any reassurance but instead reiterated that: “Bitcoin is still a work in progress, and you should only risk time or money on it that you can afford to lose.”

The debate has taken a new turn today as became unavailable for unkown reasons. Although the website was still accessible due to their CloudFlare protection, mining itself seemed to be affected and miners were not able to access their statistics.

When users visited, there was a brief 502 error which would then redirects to an old and non-live version of the website. A banner at the top stated:

“This page ( is currently offline. However, because the site uses CloudFlare’s Always Online™ technology you can continue to surf a snapshot of the site. We will keep checking in the background and, as soon as the site comes back, you will automatically be served the live version.” has not yet replied to requests for comments, but bitcoiners speculated that was DDos-ed due to ongoing concerns over their share of hashrate distribution. Many bitcoiners seemed to welcome the possibility of a DDos and one bitcoiner wondered whether he should join, while others asked for more calm.

In a recent press release in January this year stated that they would not cross the 51% threshold as it would undermine their investment. Despite this public assurance did cross the 51% threshold which might have been seen as a red line by individuals who might be capable of carrying out a Distributed Denial of service attack, but it is not yet known why the pool was down, whether it was a DDos, or who was DDos-ing them.

In a recent post on CCN, DDos-ing was suggested as a possible line of defense against a 51% attack. However, there have been no precedents of such DDos attacks in response to the share of hashrate distribution. As such, the effectiveness of a DDos attack was not clear. It is still too early to tell, but’s share of hashrate distribution stood at 38% over the past 24 hours prior to what seems to have been a DDos. It then went down to as low as 6% and has now stabilized to approximately 27%.

Although the decrease in hashrate may only be temporary, the DDos may act as a warning, not only to, but to all pools who may gain too great a share of the hashrate distribution to the point where the decentralized nature of bitcoin is placed in danger as it is likely that income would have been lost during the DDos period which may cause miners to reconsider whether they wish to partake in a pool that seems to be at the frontline of criticism.

Further updates will be provided as the story develops. If you have any information in regards to this article feel free to contact the author at [email protected] Of course the author promises to keep the information provided private and confidential.

Featured image by Shutterstock.

Updated: June 15, 2014 at 7:23 pm CET.

Join the free bitcoin trading competition and win 5 bitcoins + more here.

  • seanxcleary

    I would be more concerned about a quantum computer coming online and solving all of the remaining bit coins in a matter of hours. The US Army has reveled they have transmitted quantum data. If they can admit that then they or the NSA already has much more advanced capabilities.

  • ReworkedScripts

    alphawar06 They will only allow companies they control (which can basically be any company they want) to hold 51% so that they can change the ledger as they so desire.

  • EvanderSmart

    Greed and ego will kill GHash.  2 years from now, they’ll be nothing but a memory.
    They’re not thinking about the greater good. They will pay for their insolence.

  • Hood

    Other pools like BTCGuild for example should increase payouts. Intergrate a trade exchange and compete with GHash. Simple. People mine there because they can merge mine lots of different coins while mining Bitcoin and can trade them right then and there. If others pools did that and with very low fees or better yet no fees ( fees are ridiculous) the independent miners would leave GHash for the better pool. GHash has mostly independent miners. This is just a matter of GHash not having good enough competition. People go where the money is.

  • d57heinz

    Your request (22394) has been updated. To add additional comments, reply to this email.

    Leonard J. (CEX.IO)
    Jun 14 17:02
    Hello d57heinz,
    Apologies for the server outages, we are currently under DDOS attack, and have been for several hours. Please be patient while we attempt to mitigate this attack.
    Best Regards,
    CEX.IO Support

  • alphawar06

    The nsa will always make sure there are no 51% attacks

  • misterdna

    DDos attacks seem like a good thing in this case, but what if a smaller pool used DDos to attack larger pools, in order to gain 51%, with intent to damage Bitcoin? It seems like a relatively inexpensive attack vector, vs. the amount of damage that could be done (just based on comments by Gavin Andresen).

About The Author

Feel free to contact me at [email protected] with any information you may have. For sensitive information feel free to use my Public Key at