Blogger and blockchain expert Stepan Gershuni reported in his Telegram channel that another "51% attack"is being made on the network of the Vertcoin project. The attackers have already managed to spend a double spending of coins for a total of not less than $100 thousand. According to Gershuni, the attack became possible due to the weakness of the hardware basis of the blockchain Vertocoin, which does not require ASIC equipment for mining.
At the moment, the blockchain network of the Vertcoin (VTC) project is under attack by 51%. Stepan Gershuni, a blockchain expert, told about this in his Telegram channel. He added that the attackers managed to make at least 15 episodes of double spending of coins in the amount of not less than $100 thousand. A total of 22 chain reorganization incidents were recorded, one of which was the rewriting of more than 300 last blocks.
"Attack with the purpose of the reorganization of units was done through several separate episodes since mid-November 2018 to the present day and last for right now," said Gershuni.
He explained that such an attack could allow an attacker to execute transactions (for example, to send the coins to the exchange, wait for confirmation, sell them and withdraw BTC), and then apply the dominant, Hasrat network with the aim of creating a new alternative chain that will rewrite the history of the blockchain in such a way that it does not remain, the fact of sending coins to the exchange:
"In PoW-blockchains there is a rule of the "longest chain", that is, the chain with the maximum number of blocks is always considered true. If you mine these blocks quickly enough (faster than the rest of the network), you can rewrite history. This will allow the attacker to make another transaction and sell the same coins again. Hence the name — double spend".
He also indicated in which block an initial expenditure of about 1,300 VTC was made and which was removed from the main chain of the network and replaced during the reorganization. Then the same coins were spent in the specified block again.
As Stepan Gershuni emphasized, the problem of altcoins working on PoW algorithm is that their network works on a small amount of equipment. In addition, Vertcoin uses the so-called ASIC-resistant algorithm, that is, it does not require specialized equipment for mining:
"For comparison, in Bitcoin for the same effect, the attacker would have to accumulate power for a very long time or produce a sufficient number of ASICs, spending hundreds of millions of dollars before it becomes theoretically possible," the expert explained.
According to Coinmarketcap on December 4, the market capitalization of the VTC token is more than 988.7 million rubles. Over the past day, the trading volume has reached almost 28.3 million rubles, and the price of the coin has decreased by more than 2%.
We will note, recently the Indian scientist Saravanan Vijayakumaran the study found that "the attack 51%" on the Bitcoin network is economically useless to the attackers, as it requires "significant costs" and has no "financial return".
In turn, the developers of the project Horizon (former zencash), who suffered significant losses after the "51% attack" on their network this year, introduced the "delay function" in the consensus Protocol, which should become a reliable means of protection against such attacks in the future.