Not enough hashing power to maintain security. All it takes is one large miner, or even one dude who rents hashing power, to briefly take control of the network. It’s definitely a flaw of POW. Though, the attack becomes far more expensive to coordinate when a chain has more miners securing the network, as you’d have to “beat” 49% of the combined hashing power.
For example, as of right now, if you wanted to 51% attack Bitcoin, you’d need a hash rate of 124,619 PH/s. Which is an insane amount of power and would cost $457,893 an hour. Bitcoin Gold on the other hand.. you’d need 692 KH/s.. which would cost $327 an hour. That data came directly from here btw.
Small chains are definitely a target, though, I feel like BTG is an even bigger target since it carries a Bitcoin name tbh.
Appears this attack originated from someone renting hash power. And it lasted 10 days. Hah
The attacker mined their secret chain for nearly 10 days, renting power from NiceHash to do so.