The race is on. Alexander Hassenstein/Getty Images Flashy startups like Coinbase, Circle, Blockchain, and BitPay are some of the most famous companies in bitcoin.

But arguably more important are the miners — individuals and organisations who form the core backbone of bitcoin, ensuring the digital currency's integrity.

Bitcoin runs on a blockchain, a decentralised and public ledger of every transaction made on the network. By offering processing power towards this, users get a chance to win bitcoin — creating an arms race of miners scrambling to assemble ever-more sophisticated and powerful equipment to "mine" new bitcoin.

This decentralisation has huge benefits, but also comes with new risks: Right now, if just the top three organisations joined forces they would control 51% of the network — giving them the power to rewrite the blockchain as they see fit.

Some individuals go it alone; others join open "pools" where they combine their resources to improve their odds; some larger companies also have mining efforts. While the #1 spot can change from week to week, we have ranked the biggest mining companies using data covering August 5 to August 12 from bitcoin network analysis company Blocktrail.