Is this even legal? Can you refuse to give your phone to law enforcement? How can you protect your cryptocurrency wallet?
If the authorities are the ones who will ask you your phone, I guess you can refuse to give it to them. But if they have a search warrant or a court order for you to surrender your phone, then you cannot refuse it. Refusal means something like obstruction of justice or not cooperating to a lawful search or investigation. So the best way to safe keep your important information is not to store them in your phone.
That would be the case but we don't need to worry if we don't have any case since for sure we are still safe, but I don't think it's safe to store the details on our wallet and best to separate it the more safer place like putting it on desktop or maybe send it to another mail where people cannot reach it up.