That is precisely what I meant when I said that I encrypt my laptop and have someone else choose the password.

Is that "unkown data" as the guy above you seems to believe? Hardly. If I pack my suitcase and then just have a friend come in with a padlock to which only he holds the key and he locks it, are the contents on my suitcase unknown to me? No, they aren't. They are my belongings and I just chose, for security reasons to not only stop carrying the key on me but to not even knowing what that key is.