The incident allowed the attackers to spend the same virtual coin twice
Anybody can’t spend the same cryptocurrency for
two different transactions. For example, each transaction made with Bitcoin
is registered in a database (named blockchain) to which anyone can access to ensure
that there is no fraud; or at least that’s what we thought.
According to cybersecurity and ethical hacking
experts from the International Institute of Cyber Security, the cryptocurrency
trade platform Coinbase reported that transactions with Ethereum Classic asset would no longer be supported on its
platform, as the stock exchange found that Ethereum had been the victim of a
cyberattack that allowed a user to spend the same coin twice.
According to reports, this attack was presented
thanks to a problem known to the developers of blockchain since the emergence
of these virtual assets. The cryptocurrencies are only safe while users are
honest in maintaining the blockchain that registers the transactions. Coinbase cybersecurity expert Mark Nesbitt mentioned that this attack (known as the 51%
attack) was presented because the attackers took control over the half the
processing power of the computers that store the blockchain of Ethereum
Classic. This allowed the attackers to create alternative transactions of some
currencies, in other words, to spend twice the same coin.
Through Twitter, Ethereum mentioned that they
had detected a problem, but did not contemplate that it was a 51% attack nor
had evidence to indicate that some currency had been spent twice by the same
user. “Coinbase allegedly detected an attack, but did not contact the Ethereum
Classic team,” they mentioned.
According to reports of experts on
cybersecurity, the currencies that allegedly would have been spent twice were
worth about $460k USD. Coinbase believe that the potential to deploy this type
of attack is inherent to any cryptocurrency blockchain, so they rule out that
Ethereum Classic or any other virtual asset is especially vulnerable to a 51%
attack.
