Quote from: Texacha on Today at 08:22:03 AM

There's project supported by Bittrex, called Veriblock. They are working on fully decentralized protection against 51% attacks on small chains, using Bitcoin hashrate. They have PoP mining and I am 99% sure that no damage could be done to bigger chain (in this case Bitcoin) if someone attack small chain.

All L2 solutions work on the same principle and they make transactions in the main network at a certain interval. The hash of the network state of the 2nd level is transmitted to Call datа.
But Ethereum has no problem with a 51% attack, it is possible in theory, but it will cost a lot and I'm not sure if it can be done in practice.