Sure. They may not believe you, though.

Related example: https://en.wikipedia.org/wiki/H._Beatty_Chadwick

I'd rather have the 14 years of my life than $2.5 million I can't even use. People are weird.

There are double encryption systems. You give your "password" and they access a volume, where another encrypted volume isn't even apparent.

You can, but depending on the justice system in your area, you might not want to.