> the burden of proof is on the prosecution to prove you do have the key to it (and therefore that it is encrypted data).

If they know that you have the key, they could simply confiscate it from you to decrypt it. But how would you even prove or disprove that someone has the key?

If they arrest someone with a laptop encrypted with ransomware, will they force this person to pay? Let's say he pays or the police and gov authorities pay and the outcome would be that it's not decrypted, would it prove that this person encrypted it themselves or could it be that ransomware decryption didn't work. Does it really matter if we would be jailing potentially innocent person, I mean the terrorists and pedophiles are rampant right!?