Vertcoin (VTC) 51% Attack Attempted Using Rented Hashrate From Nicehash But Failed To Profit
The Vertcoin crypto project aiming to keep the mining power decentralized has gone through a second 51-percent attack this year.
603 genuine blocks on Vertcoin’s main blockchain were replaced by the attacker with 553 blocks, says James Lovejoy, the lead maintainer for the project in a notice on GitHub.
The incident took place on December 1st and had the blockchain reorganization causing 5 “double spends” to 125 Vertcoin (VTC), which is worth about $29. This is what Lovejoy had to say about the attack:
“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.”
What Is a 51-Percent Attack?
A 51-percent attack takes place when an entity or perhaps more entities gain more than half from a blockchain network’s hashing power. It makes it possible for the blocks that make up the chain to be rewritten.
Exactly one year ago, Vertcoin had another attack of this type, attack that caused many reorgs and was estimated to have costed more than $100,000.
Following that, Vertcoin, which is aiming to block the ASICs powerful mining chips from the network in order to keep mining affordable, has switched from the Proof-of-Work algorithm and adopted the Lyra2Rev3 one. This is what Lovejoy had to say about the situation further:
“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.”
He added there’s evidence proving the attack has been carried out after the Nicehash hashrate has been harnessed.
It’s Unclear Why Vertcoin Got Attacked for the Second Time
No one seems to know why Vertcoin was attacked again. Lovejoy says no profits could have been gained only from the mining block rewards. He thinks the target may have been Bittrex.
The fact that Bittrex is disabling the Vertcoin wallet could have prevented the increase of double spends. Another idea is that no theft through double spending was the plan and the attack was meant for sabotaging or as a proof of concept.