There was a case where that defense was mounted, but failed [1]. The encryption keys were deemed to exist "separate from the will of the subject" i.e. they were

There was a case where that defense was mounted, but failed [1]. The encryption keys were deemed to exist "separate from the will of the subject" i.e. they were deemed to be "physical". You can't use the defense against self-incrimination for physical keys either and the prosecution likened the encryption key to a physical key. What hasn't been tested in court (afaik) is the refusal to hand over a passphrase that protects the encryption key. If the passphrase exists only in your head, it could be argued that it doesn't exist separate to your will. [1] http://www.theregister.co.uk/2008/10/14/ripa_self_incrimination_ruling/ http://www.theregister.co.uk/2008/10/14/ripa_self_incriminat...