According to a reddit user, back in January, crypto mining marketplace NiceHash controlled more than 70 per cent of the hashrate for DASH, a cryptocurrency worth over $500 million, making the token potentially in danger of a 51% attack. NiceHash itself had the power to initiate the attack; moreover, a hostile entity could theoretically lease enough power from NiceHash to organize the attack—blocking the blockchain and double-spending coins.
NiceHash disputes these claims, saying it stands against 51% attacks, stating “such deliberate and harmful actions should be taken very seriously.” However, it does not address the danger its position could cause—instead, it offers smaller cryptocurrency miners to join them in an attempt to stop potential 51% attackers from gaining enough hash power.
“NiceHash is giving everyone with smaller and less secure blockchain projects the option to make them more secure by leasing hash power,” NiceHash wrote in a statement. “If you think your network is under attack (although such an attempt is extremely complicated and requires a very high level of skills and resources), you can mitigate such attacks and further secure the network by using NiceHash!”