Vertcoin Suffers Its Second 51-Percent Attack In a Year

Vertcoin, a cryptocurrency venture that intends to keep mining power decentralized, has endured its second 51-percent attack in a year. 

The occurrence saw 603 authentic blocks on the Vertcoin primary blockchain supplanted with 553 blocks written by the attacker, as per the initiative’s lead maintainer, James Lovejoy, in a GitHub notice.

Happening on Sunday, December 1, the blockchain reorganization caused five “double spends” to the value of 125 vertcoin (VTC) worth around $29. “Each of the double-spent outputs are coinbase outputs owned by the attacker and it is unknown to whom the coins were originally sent before being swept to an attacker address after the reorg,” Lovejoy stated.

In other words, a 51-percent assault can happen when an organization increases over half of the hashing intensity of a blockchain network, bringing the capacity to rewrite the blocks making up the “chain.”

Exactly a year prior to the day, Vertcoin witnessed another 51-percent attack that resulted in various reorgs and was assessed by Coinbase to have cost clients more than $100,000. After that attack, Vertcoin – which intends to block ground-breaking mining chips dubbed ASICs from the network to continue mining more community-based and reasonable – switched its proof-of-work algorithm to one dubbed Lyra2REv3.

The most recent attack had been seen coming. Lovejoy clarified:

“On Nov 30th 2019, a Vertcoin miner noticed a large upswing in hashrate rental prices for Lyra2REv3 on Nicehash. This was combined with workers connected to Nicehash’s stratum server being sent work for unknown (non-public) Vertcoin blocks. I contacted Bittrex, Vertcoin’s most prominent exchange, to recommend they disable the Vertcoin wallet on their platform once it became clear an attack was in progress, which they subsequently did.”

The developer further said there’s “strong evidence” that the attack was made by outfitting leased hashrate from Nicehash.

“The attack was originally discovered by inspecting the work being sent from Nicehash’s stratum servers, which were sending work for non-public blocks,” he stated.

It is not clear why Vertcoin was attacked again. Lovejoy stated it would not have been productive dependent on miners’ block rewards alone. He said Bittrex might have been target, but the exchange disabling its Vertcoin wallet may have avoided all the double spends.

An alternative choice is that robberies by means of double spending were not the arrangement, and the attack may have been “a proof of concept or sabotage attack.”