Originally posted here by catch I have seen a few systems like this already...... that ask three simple questions. typically the user answers 10-20 questions when setting up the account. Of which 1-2 of the questions are fakes, eg: "When was your last trip to Europe?" If you've never been and this wasn't selected from the original set and you answer it, even if your other answers are correct this will act as a duress alarm.
I hate to be the botheration in this thread, but are these systems modeled after the traditional models (Bell-La Padula, Biba (I know those only address reads and writes), lattice etc..)? What are the design principles and concepts? What model or models are these modeled after (designs)? If you're at leisure to divulge this information?
Forgive for my ignorance, I'm just trying to learn.