"Microsoft, Symantec, and 20 other companies have been sued by a small Texas firm for patent infringement. The firm was granted patents in the mid-'90s over systems for governing application and data permissions, as well as ensuring application integrity, and is now seeking to bar the companies from making use of the patents. And some monetary damages would be nice, too. The firm, Information Protection and Authentication of Texas (IPAT), owns two patents cited in its complaint, the latest of which is US patent 5,412,717, which was filed in May 1992 and granted on May 2, 1995. This is a continuation of a previous patent, US number 5,311,591, granted in May, 1994. Titled "Computer system security method and apparatus having program authorization information data structures," the former patent essentially describes a system of authorization and permissions when executing applications and processing user data."