With a decentralized structure, no one group should be able to have undue influence or control over Bitcoin. That idea is now being tested as a pair of Cornell university researchers revealed that a Bitcoin mining collective called Ghash.io managed to represent 51 percent of Bitcoin mining power as of June 13. With Bitcoin, as with all cryptocurrencies, new coins are created through a computing-intensive process known as mining.
With 51 percent of mining power in the hands of a single group, the Cornell researchers see a real risk.
“Ghash is in a position to exercise complete control over which transactions appear on the blockchain and which miners reap mining rewards,” the researchers wrote in a blog post. “Bitcoin is currently an expensive distributed database under the control of a single entity, albeit one whose maintenance requires constantly burning energy—worst of all worlds.”