> Perfect Forward Secrecy means that even if you want to you cannot decrypt old messages
Which means, if they're jailing you until you do decrypt the messages, you get jailed indefinitely. Contempt of court has very few limits in some circumstances, even compared to being imprisoned after being convicted of a crime:
> Which means, if they're jailing you until you do decrypt the messages, you get jailed indefinitely.
Maybe, but they wouldn't be waiting for you to do something for them. They would understand that there was nothing you could do to help them decrypt the messages. i.e. your encryption worked.
However, unless there is a legal requirement that you maintain the records in question, a documented habit of destroying them is almost certainly enough to get out of contempt of court for not producing them, absent some specific reason to believe you kept those special.
Which means, if they're jailing you until you do decrypt the messages, you get jailed indefinitely. Contempt of court has very few limits in some circumstances, even compared to being imprisoned after being convicted of a crime:
http://caselaw.findlaw.com/us-3rd-circuit/1262859.html