Vertcoin Suffers its Second 51% Attack in 12 Months

Vertcoin recently suffered its second 51% attack in 12 months, with the newest attack occurring almost exactly 1 year since the previous one. Reports of a 51% attack on the project known as Vertcoin (VTC) has flooded the web in the last few hours. The attack reportedly took place on December 1st at 15.19 UTC, […]
Vertcoin recently suffered its second 51% attack in 12 months, with the newest attack occurring almost exactly 1 year since the previous one. Reports of a 51% attack on the project known as Vertcoin (VTC) has flooded the web in the last few hours. The attack reportedly took place on December 1st at 15.19 UTC, […]

Vertcoin recently suffered its second 51% attack in 12 months, with the newest attack occurring almost exactly 1 year since the previous one.


Reports of a 51% attack on the project known as Vertcoin (VTC) has flooded the web in the last few hours. The attack reportedly took place on December 1st at 15.19 UTC, when around 603 blocks got removed from the project’s main blockchain. Simultaneously, the attackers replaced them with 553 of attacker blocks.

According to reports, there were around 5 recorded transactions that included double-spending, while the hacker managed to ‘earn’ around 13825 VTC coins from block rewards, which is around 0.44 BTC ($3,211).

However, one interesting detail regarding the attack is that it took place exactly a year after the previous attack, Bitcoinist reported in early December 2018.

Vertcoin Falls Victim Again

Reports of Vertcoin (VTC) suffering a 51% attack started emerging in early December 2018, when the project experienced 22 deep chain reorganizations. 15 of them reportedly included double-spending of VTC. In the aftermath of the event, it was estimated that attackers had stolen around $100,000, while the largest reorg went 300 blocks deep, according to last year’s Medium report by Mark Nesbitt.

Now, a Github user known as metalicjames, who is Vertacoin’s lead maintainer, James Lovejoy, reported that the attack happened once again. According to the report, the project abandoned the PoW algorithm after the last attack, and shifted to Lyra2REv3. While developers believed that the project was safer for it, one of the miners started noticing an unusual upswing in hashrate rental prices on November 30th, 2019.

Since Bittrex is Vertcoin’s most trafficked exchange by volume, the exchange was notified of the suspected incident and advised to close its wallet to the coin. Bittrex reacted by disabling withdrawals as soon as they received proof that the project was under a 51% attack.

The motive remains unclear

For the moment, developers suspected that attackers used the hashrate rental service, Nicehash. Lovejoy believes that the attacker spent between 0.5 and 1 BTC to perform the attack, indicating that their efforts were not exactly profitable.

This leads to the question — why conduct the attack at all? Vertcoin is currently 194th largest cryptocurrency, with a market cap of $12.5 million. Meanwhile, its trading volume in the last 24 hours sits at $363,000. The coin’s price is currently at $0.236971, after suffering a 6.84% drop in the last 24 hours.

With the date of the attack being exactly one year since the last one, and the fact that the attack was not at all profitable, it appears that the hacker(s) had a different goal in mind. Lovejoy speculated that the attack might be proof-of-concept sabotage.

Alternatively, the real target of the attack may have been Bittrex itself, although Lovejoy points out that the double-spend portion attack was aborted even before the exchange disabled their wallet. In other words, PoC sabotage seems like the most valid explanation as of now.

Do you think that two attacks on Vertcoin are connected? Let us know in the comments below.


Image via Shutterstock,  Twitter @metalicjames