Over $70,000 Double Spent As Bitcoin Gold Experiences Its Second 51% Attack

New information indicates that Bitcoin Gold experienced a 51% attack last week. A total amount of over $70,000 was double-spent, which raises questions regarding its security since this is the second similar attack on the network.

51% Attack On Bitcoin Gold

A 51% attack occurs when a single organization or entity takes control of the majority of a particular network’s hash rate. Once its executed, the perpetrators have control over the transactions to modify the ordering, prevent them from being confirmed, reverse them, or facilitate double-spending.

The last one is what has happened to Bitcoin Gold, according to a recent report. It shows that on Thursday and Friday last week, there were two deep reorganizations on BTG transactions that ultimately led to double-spending.

The first one was for 1,900 BTG (approximately $19,400 in today’s rate). The second one was completed in three different batches, and the total amount was for 5,267 BTG (nearly $54,000).

Bitcoin Gold is a hard fork of Bitcoin and uses Equihash (144,5) or Zhash. Unlike the largest cryptocurrency’s hash rate, which is continuously increasing, BTG’s hash rate has noted a severe decline since the middle of 2018. Naturally, this leads to a less secure network, which is the reason why such an attack can occur a lot easier.

Bitcoin Gold Hash Rate. Source: https://bitinfocharts.com

Not The First Time

The 51% attack that happened last week is not the first one in Bitcoin Gold’s relatively short history. Back in 2018, BTG recorded the first one, which had significantly more harmful consequences.

Confirmed in a blog post, the previous attack targeted cryptocurrency exchanges. At that point, Bitcoin Gold officials said that “we have been advising all exchanges to increase confirmations and carefully review large deposits.” However, the hackers ultimately fabricated BTG’s ledger and managed to defraud at least $18 million in total.

Ethereum Classic also went under a similar attack last year. The total amount stolen by the double-spending hack was 88,500 ETC (worth around $460,000 at the time.) Interestingly enough, the attackers later returned a part of the stolen ETCs.