After the 2 Verge/XVG 51% attacks i’am very carefully when i read 51% attack. In the case of Verge i turned out that as much as 1% hashpower had been enough to perform that timestamp spook attack and that’s why i think the term 51% attack should be very carefully used.
I’am not familar with BTG at all. But checking their last 10 days network hashrate i can not see any increase coming from somewhere, the network hashrate looks normal. That doesn’t exclude a 51% attack of course.
What i wold like to see is actually proof it’s a 51% attack with indeed 51%+ Hashpower and not exposing some coding bug, Timestamp spoofing and/or something similar …
About the hashingpower to lease. For the BTC hashingpower it’s pure SHA256 hashing power that can not leased/sent elesewhere. For the Ethereum hashingpower it’s different of course and may hit wherever a bad actors would like to hit.
And i wouldn’t call Zcash a “smaller coin”, it has a decent network with 10+x times the BTG network.
But i agree that smaller coins/projects with very small networks are indeed in danger, but than again, an attacker wants to make money and small projects/coins aren’t a good target with less exchanges, less value, less demand, less volume … Once a project gains in value/price it network hashrate normally goes up as well and reverse of course, see Bitcoin Gold where the network went from 53 to 20 Mh/s.
Because the coin is worth more so more miners mine the coin. The more valuable the coin the more secure it is regardless of whether it is GPU mined or ASIC mined.