Vertcoin cryptocurrency network fell victim to attack 51%

On Sunday, December 1 the Vertcoin blockchain experienced attack 51%, but it turned out to be not entirely successful for its organizers as the profits did not cover the costs of the attack.

Vertcoin' lead developer James Lovejoy reported the unsuccessful attempt to carry out an attack on the network.

He noticed that on November 30 the cost of renting resources for Lyra2REv3 algorithm used by Vertcoin grew significantly. While on December 1, an unknown attacker removed 603 blocks from the main Vertcoin network and replaced them with their own 553 blocks.

However, the attacker faced some issues.

Based on the market prices during the attack's preparation and the difficulty of the blocks the attacker produced, we estimate the attacker spent between 0.5-1 BTC to perform the attack. The total value of the block rewards the attack received is 13825 VTC (~0.44 BTC). Given the attack was likely not profitable to perform based solely on block rewards, the motivation for the attack is not certain, James Lovejoy wrote.

He also noted that after he contacted Bittrex, the largest marketplace for VTC, the exchange blocked its wallets.

Given the reorg was just deeper than 600 blocks (Bittrex's confirmation requirement for VTC), it is possible that Bittrex was the original target, but the double-spend portion attack was aborted due to Bittrex disabling their wallet before the fork could be released, Lovejoy wrote.

He also suggested that the attacker did not initially set the goal of double spending and carried out an attack to check the stability of the network or sabotage.

Vertcoin is a fork of bitcoin that exists since 2014. It takes the 194th place in the CoinMarketCap rating. Over the past 24 hours it lost 10% of its value to trade at $0.235 at the time of writing.

This is also not the first case of a 51% attack on Vertcoin - the previous such incident happened in December 2018.