The Vertcoin blockchain (VTC) suffered a 51% attack on Sunday, December 1, in which 603 VTC blocks were replaced by 553 blocks made by the attacker. This is the second time that the Vertcoin chain, which is resistant to ASIC has been attacked. The network underwent a reorganization of 300 blocks last year.
The information is from Bitcoin.com website.
Vertcoin, a fork of the Bitcoin protocol, is an alternative cryptocurrency that has been around since January 2014. The community and developers behind the project believe that VTC is different because they claim the mining protocol is resistant to ASIC processors. However, during October and December 2018, the Vertcoin network dealt with a series of 51% attacks and several blockchain reorganizations (reorg).
A 51% attack occurs when a single entity (mining company) occupies more than 50% of the network's hash power, allowing for block reorganization, specific transaction validation, and other activities that can lead to double cryptocurrency spending.
The reorganization of 300 blocks in Vertcoin last year caused more than $ 100,000 in double spending. The situation called on the VTC developers to change their proof of work algorithm to another algorithm called Lyra2rev3.
Now, less than a year later, on December 1, 2019, the Vertcoin network suffered another 51 percent attack, even using the new PoW protocol to ensure more resistance to mining pools. James Lovejoy, lead developer of Vertcoin, explained the situation:
“On Sunday, December 1, 2019, 15:19:47 GMT 603 blocks were removed from the VTC main chain and replaced by 553 attacking blocks. We note that 600 blocks is the current confirmation requirement for VTC in Bittrex. There were 5 double spend exits where ~ 125 VTC (~ $ 29) were redirected. Each of the double spend exits is owned by the attacker and it is not known to whom the coins were originally sent before being swept to an attacking address after reorganization. ”
As with last year's attack, the captured hashrate was blamed by Nicehash. The company sells hash power to individuals and acts as a hashpower broker market that connects sellers and miners. Lovejoy noted that he noted on November 30 "a large increase in hashrate rental prices for Lyra2rev3 in Nicehash."
