Crypto is more or less illegal in my country. How can I hide it legally?

I live in a country where cryptocurrency is somewhat illegal. I would like to purchase crypto on a centralized exchange and withdraw it to my wallet. Then, I want to hide the funds from the public. I am not looking for mixers or tumblers. Instead, I need a method or strategy that would allow me to later prove the source of funds to exchanges and banks. Is there a protocol, exchange, tool, coin, or token that would let me do this? Being able to link the wallet of origin to exchanges and banks later is a must.