Patent ID: 8024530

Claim:
A computer system comprising: a processor; a first physical storage device residing within said computer system or attached to said computer system through an external bus; any of a plurality of operating systems encompassing a file system; a database, stored in said storage device, said database comprising: a plurality of sets of data patterns, each data pattern is designed to minimize the possibility that once-written over existing data on one of a plurality of physical media types will not be recoverable from said physical media of said physical media type; said computer system running a first software program that detects when a file residing on one or more allocation units of said first physical storage device has been deleted by virtue of said operating system notifying said first software program when a file has been deleted, selects from said database one of said data patterns intended for overwriting data on said first physical storage device based on said physical media type of said first physical storage device and writes said data patterns on said allocation units comprising said deleted file; and a second software program that operates to examine data contained on each allocation unit not assigned to a file, determine if the said data contained on said allocation unit not assigned to a file is not the same as the said data pattern contained in said database for said physical media type, said data pattern will be written on said allocation unit.