A method and apparatus for protecting secured files stored on a file system employs
a file security status associated with each file to signal whether or not access
to the file is allowed. The file security status is stored in a fixed location
in memory. Upon opening the associated file, the file security status is copied
to a second location in memory. Depending upon the file security status stored
in the second location, operations on the file by a client are either allowed or
denied. Operations on non-secure files are always allowed. Operations on secured
files are allowed only after verification of the client's authorization to access
the file and the subsequent modification of the file security status stored in
the second memory location. The method protects secured files from deletion by
unauthorized clients. This is accomplished by, upon opening a secure file, initializing
a third memory location to a value indicating that the file will not be deleted
upon closing. This value may be changed by an authorized client only after going
through the above-described verification process. Once the value has been changed
to reflect that the file should be deleted when closed, the file will be deleted
when closed. A method for creating a new secure file is also provided.