For Windows 8, Microsoft is a preparing a new way to log in to tablet PCs by letting users perform gestures on the screen instead of typing in letters and numbers. A user will choose a photo with some personal meaning to them, and create a sequence of taps, lines, and circles which must be performed in the right order to unlock the computer.
The obvious question is whether such a system is as secure as typing a password on a keyboard. Given the kinds of simple passwords many users rely upon, the gesture-based system could well be more secure for numerous people. Microsoft acknowledges that smudges on the screen or recording devices could theoretically allow the gesture password to be compromised, but says the risk is very low.
Windows 8 gesture login: Can screen smudges reveal your password?