Bitcoin currently is taxed only by the South Korean govt. at a rate of around 23%. But tax can be collected merely on amount which you withdraw in exchanges. So the simple rule to save tax on all your crypto earnings is to store the bitcoins in a private key wallet where you don't need to do any KYC compliance. So you are anonymous just with your wallet address. But the problem is that you won't be able to get a fiat conversion of your bitcoins until you bring them to exchanges.