Ethereum classic, a spin-off of the world’s second most popular cryptocurrency, has been hit by a series of major attacks on its blockchain network.
Unknown hackers made away with more than $1.5 million (£1.2m) by performing a so-called 51 per cent attack on ethereum classic’s underlying technology.
Popular cryptocurrency exchange Coinbase was forced to cease trades of ethereum classic as a result of the attack.
Coinbase told its users in a blog post that more than $1.5 million had been lifted by hackers through the double spend event.
“Coinbase detected a deep chain reorganisation of the ethereum classic blockchain that included a double spend,” the blog post stated.
“In order to protect customer funds, we immediately paused interactions with the ETC blockchain. Subsequent to this event we detected… additional reorganisations that included double spends. We will continue to monitor the status of the network.”
A 51 per cent attack is technically possible on any cryptocurrency, though by its nature it is very difficult to carry out.
It involves taking control of more than half of the network’s mining computer power, which is used to both generate new units of the cryptocurrency and confirm transactions on the network.
This allows for something called ‘double spend’, whereby whoever is in control of the network can spend units of the cryptocurrency twice.
Bitcoin’s pseudonymous creator Satoshi Nakamoto first described this type of attack in their 2008 white paper.
The paper stated: “If a majority of CPU power is controlled by honest nodes, the honest chain will grow the fastest and outpace any competing chains.”
Ethereum classic is currently ranked on CoinMarketCap as the 18th most valuable cryptocurrency, however the latest attack is likely to damage traders’ trust in the asset.
Previous 51 per cent attacks on cryptocurrencies like bitcoin spin-off bitcoin gold have resulted in a decrease in their value.