The US Patent Office has granted Micron a patent covering a "system and method for controlling user access to an electronic device" . Could this be enough to overthrow Apple's slide-to-unlock patent claims?

The patent awarded in January 2013 to Micron Technology and now published as US 8352745 B2 is for a method of authenticating users by matching the geometric pattern they input to a touch screen with a previously stored pattern.

It cites the inventor as James McKeeth and includes reference to a related patent application filed in February 2000 and issued as US Patent No 6,766,456 BI.

Drawing attention to Figure 3C of the patent application, an upward swipe or slide, Denis Crouch writing on the PatentlyO blog makes two salient points regarding the ongoing smartphone wars:

• Apple's slide-to-unlock patents claim priority only to the 2004-2005 timeframe and, although they may be separately patentable, Apple's patents will not serve to invalidate Micron's new patent.
  
  
• Samsung has a 10-year cross licensing deal with Micron (set up in October 2010) - and doesn't have similar deals with Apple, Google/Motorola or RIM
  

He also speculates as to whether Micron will hold on to the patents or pass them on "for enforcement" - which could be bad news for several mobile phone manufacturers.