A known cryptocurrency may have suffered a breach of trust

An important exchange of cryptocurrencies has announced that it has suspended the movement of the famous classic criptovalute token ethereum after detecting a potential attack on the underlying technology of digital money.

Coinbase exchange and portfolio company said they had identified a so-called "chain reorganization" in which almost two and a half million dollars of classic ethereum were spent – an extremely rare anomaly for cryptocurrencies, but it represents one of the greater threats to the success of technology.

It could be the result of what is known as a 51% attack, exposing a potential flaw in the underlying cryptocurrency technology known as blockchain.

Basically, Coinbase is saying that an ill-intentioned party may have been able to tear up more than 50% of the ethereum classic network, and therefore was able to dominate decisions about what belonged and did not belong to the coin blockchain digital: the digital ledger that depends on a widespread consensus among users to record the history of the asset.

In theory, the registers of a blockchain can not be modified because a sufficient number of disparate parts is incentivized to maintain an accurate accounting of who owns what. But a 51% attack can change that calculation, allowing someone to falsify transactions and spend the same participation more than once, substantially undermining the usefulness of a digital payment system and the trust of people in it .

Ethereum, the "classic" cryptocurrency in its name, is the second largest digital token in the world, with a market capitalization of over $ 15 billion, according to CoinMarketCap.

The team behind classic ethereum said that Coinbase did not try to connect with it and is still a "process in progress". In a separate Twitter post, the team said it was not trying to minimize the events, but there is still a lot of work to do to find out what happened.

"The facts are made and as the situation develops, we will soon have a complete picture of what actually took place," tweeted the classic Twitter account of ethereum.

Like bitcoin, ethereum is based on blockchain technology, where computers compete against each other to solve complex mathematical problems that in turn create a distributed, secure and transparent system that can have a variety of applications.

Supporters of blockchain technology often talk about network security, but a 51% attack is one of the flaws. Currently they are quite rare but have occurred in some cases, in particular with smaller cryptocurrencies. Last year, litecoin cash and zencash both suffered 51% of attacks. It is thought that the size of a cryptocurrency network is therefore a defense: it becomes prohibitively expensive to hire more than half of a gigantic distributed system.

Tuesday morning, ethereum classic had a market capitalization of over $ 500 million. This is in stark contrast to the capitalization of nearly $ 70 billion bitcoins, but still means the token rank in the top 20 cryptocurrencies measured by CoinMarketCap.