Attack On Ethereum Classic Unconfirmed, But Very Likely

The Ethereum Classic (ETC) blockchain is currently undergoing deep reorganizations that indicate a 51% attack may be underway. The security firm SlowMist reportedly alerted the Ethereum Classic community of the problem on Monday, and a number of other sources are in agreement. However, Ethereum Classic itself has denied that anything is out of the ordinary.

Although Ethereum Classic refuses to jump to a conclusion, the group has urged exchanges and mining pools to take action and increase their confirmation times, indicating that something is amiss. According to Ethereum Classic, this will prevent a 51% attack, suggesting that an attack is possible but has not yet occurred. However, one mining pool called Bitfly has asserted that a successful 51% attack has already taken place.

Meanwhile, the Coinbase Blog is remaining impartial and has stated that “deep reorganizations” are occurring on the blockchain, only some of which contain double spends. Although those double spends have cost $1.1 million so far, they apparently have not affected the exchange directly. However, there is still cause for concern: the blog’s meta title states that the chain is “currently being 51% attacked,” and Coinbase has paused ETC transactions for the time being.

Suggested Reading : Learn how Coinbase compares to Bittrex.

Despite the lack of an official confirmation from Ethereum Classic itself, the blockchain is undeniably vulnerable to such an attack. The coin was the result of an Ethereum fork that took place in 2015, meaning that Ethereum Classic has a significantly smaller mining community than its parent coin, as well as a significantly lower hashrate.

Past estimates suggest that an attack on Ethereum Classic would cost $1.5 million, although up-to-date sources put the cost much lower. Crypto51 predicts that an attack on the Ethereum Classic network would cost just $4556. This means that an attack on Ethereum Classic would be roughly in line with the scope of previous attacks on other blockchains.

Over the course of 2018, a handful of 51% attacks successfully targeted several small altcoins. The largest attack concerned Bitcoin Gold, but other minor coins such as Verge, Zen, Litecoin Cash, and Pigeoncoin were also targeted. An attack on Ethereum Classic would be significant by comparison, but still within reach of attackers.

In any case, it is still not clear what exactly is behind Ethereum Classic’s unusual network activity, and an attack is not a foregone conclusion. Some are speculating that the strange activity is related to a previous attempted takeover of ETC by the Digital Finance Group.

Ethereum Classic itself suggests that large-scale ASIC testing by the miner manufacturer Linzhi could be the cause. Mining pools are certainly playing a role in some way. It is hard to say exactly what is happening with any certainty, but as costs to the network grow, an outright attack becomes a more likely cause.