Bitcoin Gold Hit By 51 Percent Attacks, $72,000 In Cryptocurrency Double-Spent

Any entity that controls more than 51 percent of a blockchain’s hash rate can decide what version of the blockchain is accepted (or rejected) by the network. These scenarios also allow for “double-spending,” attacks that initiate a transaction with intent to quickly reverse it by “re-organizing” the blockchain, so that they can spend their original cryptocurrency again. What results is a third party accepting the original transaction and the network returns the cryptocurrency spent to the attacker, essentially allowing their funds to be used twice — hence the name “double-spending.” With Bitcoin, a transaction is generally deemed legitimate once found six blocks deep in the blockchain. These particular 51-percent attackers performed re-organizations up to 16 blocks deep, seemingly in a bid to trick exchanges like Binance into paying out BTG destined to be double-spent.