Torture, for example. The only way to protect the asset from them would be to store it in your head, and be willing to take it to your grave, too.
Discussion
Yes, torture is a way to obtain consent. But torture is messy and unpleasant business. No one is going to exert that level of effort unless they are sure of the outcome.
So store it in your head and keep your mouth shut.
^ This.
Or imprisonment in a work camp until you cough up. Sucks to be you if you genuinely don't have it.
Stalin had his "Gold Rush" in the same year as Roosevelt, but Stalin had the machinery ready to go to torture the gold out of everyone, and Roosevelt did not (but Roosevelt had KYC records to go after).
Current Western governments have both sets of capabilities.
Avoid KYC!