If you had two password for a login, would that be evident in your shadow/passwd file, thus destroying your plausible deniability?
Also if you looking of PD in the US Court system, you can use external keys on a USB or Smartcard et cetera. In the US court system, if you won't give up your password, then they can put you in jail until you do. However they can't force you to give up your key. Just make sure its well hidden.
Last edited by wsduvall; 04-02-2009 at 08:41 AM.