The solution to this seems to be straightforward. A one use decryption key is generated in another country. If sent to you on request, it will decrypt your files once. Once a week or so, you must provide that foreign source with a ping of some description, or it will no longer provide you with a key. Your files will be locked for good.
Of course this will require all sorts of security additions, maybe even multiple keys from multiple countries. And the hassle of having to ping some address once a week.
The downside is that in some cases, judges are citing for contempt even if you are unable to produce what they want. A man in Philadelphia was just released after being held for contempt for 14 years on the belief that he had hidden money from his ex-wife in a divorce case.
While this is terribly unfair, unless you give them the tools to convict and punish you, you may very well be punished.
That would be H. Beatty Chadwick, a man kept in prison for 14 years on civil contempt charges. A judicial travesty that should have never happened. A victim of a group of black robed thugs.