At least you can fake that out by pressing the wrong keys. Similar to how I enter my PIN into ATMs, I have my fingers covering all the keys at once with my ha

At least you can fake that out by pressing the wrong keys. Similar to how I enter my PIN into ATMs, I have my fingers covering all the keys at once with my hand open and my palm down. All the keys get touched, albeit with different amounts of pressure, but picking up that sort of difference would be error prone.