I was thinking that decrypting is similar to forcing someone to unlock their safe and I don't have a problem with this. However, the more I think about it I see it as a secret code. If I invent my own language XYZ and write everything down with it, can they compel me to translate my documents back to English? Or force me to give them an XYZ to English dictionary? The decryption password to me is the same thing as a translation dictionary.