On the background of the collapse of the cryptocurrency market, more and more miners turn off their equipment as a consequence of the reduction can see the network and increase the risk of implementation attacks on her 51%. The risk group also includes little-known cryptocurrency. This attack was carried out in mid-November on cryptocurrency Vertcoin (VTC), located at 188 place in terms of capitalization.
As the safety engineer for Coinbase mark Nesbitt, the attack occurred in mid-November. Using the attack 51%, the hackers had at least 15 episodes of double-spending of coins worth more than $100 000. In total there were 22 cases of reorganization of the chains, one of which was to rewrite more than 300 of the latest blocks.
Attack to reorganize blocks allow attackers to execute transactions (for example, to send the coins to the exchange, wait for confirmation, sell them and withdraw bitcoins), and then use the dominant, Hasrat network with the aim of creating a new alternative chain. As a result, the history of the blockchain will be rewritten in such a way that the entry about sending coins to the exchange will not be saved and the attacker again can sell or move the same coin.
According to the news service crypto51, 1 hour of network attacks zloumyshlennika Vertcoin will cost $104.