Microsoft has submitted a patent claim for its Windows 8 sketch-based password authentication feature.
The patent, numbered 8,024,775, was originally filed on 20 February, 2008, but was only approved yesterday, giving Microsoft legal protection for its novel approach to device security.
The patent covers a graphical method for password authentication.
The picture password feature allows Windows 8 users to select their own personal picture and sketch three different patterns over the picture to login. The new authentication system makes it easier for tablet and touch users to login to a Windows 8 PC.
In some ways the feature is similar to image and text recognition technology such as optical character recognition (OCR) for scanning.
“The technique may be implemented on a computing device, such as a PC or a portable electronic device, for authenticating user logon,” says the patent summary describing the feature. “Users can draw any sketch he or she desires as a password.” Microsoft introduced the feature as part of its Windows 8 Developer Preview, released last week.
Microsoft notes that the feature is “particularly suited for protecting information on devices such as the PDA, Tablet PC, and game devices such Nintendo-DS, where the stylus is a major input means.”
The technology will feature in Windows 8 as Picture Password, both in its standard desktop and mobile Metro interfaces. Users will be able to select an image of their fancy and then make several touch or mouse-based gestures over certain parts of the image as a way to log in.
For example, if a user picks an image of a person’s face, the gestures could be a tap on either eye and a semi-circular movement around the mouth. More detailed pictures could end up like a Where’s Wally? book, tapping or clicking various hard to find objects on the screen.
Microsoft explains that the system does not authenticate users based on an exact match of their drawing. “It authenticates based on the future similarity between an edge orientation pattern extracted from the sketch the user enters and an edge orientation pattern extract from the user’s pre-registered template sketch,” explains the patent filing.
The feature, demonstrated below, is particularly useful for touch-based devices but also works well on a standard keyboard and mouse setup in Windows 8.