Abstract or Summary:
Authentication on mobile devices is not (and should not be) the same as on desktop and laptop computers. The differences span not only the device itself and how we interact with it ("bursty" pattern where we pick it up frequently but for short periods of time) but also with the touch screen interface provided on many mobile devices. Frequent, effortful authentication reduces the usability of any authentication method and runs the risk of annoying the user to the point that they disable it. Given that mobile devices often store sensitive information about their owner, disabling authentication has the effect of putting the data it stores at risk.

Simply deploying a method on mobile devices that is usable and useful on a desktop or laptop computer will not suffice. A new method that respects the mobile device environment is necessary.