Last week, the miner-attacker has performed a successful double-spend attack on the Bitcoin network Gold (BTG). Director of communications at Bitcoin Gold Edward sparkle for the first time warned users about the attack on 18 may, explaining that the attacker uses an exploit that allows you to steal money from cryptocurrency exchanges.
To attack the miner assigned at least 51% of the total hash power of the network, and it would give him temporary control over bloccano. To achieve a similar hash power using equipment is incredibly expensive, even within such a small network like Bitcoin Gold, but it can be monetized due to the double-spending attack.
Having control over the network, the attacker (or attackers) began to Deposit BTG exchanges, in parallel trying to send the same coins in your wallet. Usually in this situation includes the blockchain in a block only the first transaction. However, a hacker could cancel the transaction, as controlled network.
As a result, he was able to contribute to the exchange and quickly pull them out, and then cancelled the original transaction to send initially deposited coins to another wallet.
Since 16 may, the Bitcoin wallet of the Gold involved in the attack, got 200 388 BTG (mostly due to those transactions which he sent to himself). If all these transactions were related to the exploit of double spending, it can be assumed that the unknown stole on the exchanges of approximately $18.6 million
The last transaction was sent on may 18, however, theoretically the attack could be renewed, if the attacker still controls the blockchain.
The developers BTG encouraged exchanges to increase the number of confirmations required to ensure that customers could transfer funds into their account. According to the team of Blockchain, an attacker successfully canceled transaction 22 blocks, so developers are advised to confirm 50 units.
Currently, Bitcoin Gold takes 27th place in terms of capitalization and turnover this cryptocurrency is $783 million This coin is the third altcon, which became recently a victim of network attack.
Recently unknown miner used two hash algorithm confidential coins Verge to bypass the rules mined over 35 million XVG $1.75 million in just a few hours. Earlier the Japanese cryptocurrency, Monacoin, in turn, was attacked with the grip, and the hacker got 57% of the hash power of the network.