Can I fork an existing blockchain

Question

I would like to know if it's possible to only allow my tokens to be used on that blockchain. 

 If so, how could I achieve it? Because, for example, if you use the Ethereum or QTUM blockchains I think all ERC20 or QRC20 contracts can be deployed there, which I don't want.

Or do I have to create my blockchain from scratch?

Answer 1

You know it's important to realize what these tokens really are - smart contracts typically containing mapping. So by saying you don't want tokens on your blockchain, you are basically saying you don't want smart contracts???

Even if you could prevent people from implementing the ER/QRC20 interface they would still be able achieve the same functionality in many different ways. But remember that in the end your blockchain is fueled with its own coin, your coin, not the ER/QRC20 tokens.