A device includes a computer processor and a file store coupled to the
computer processor. The file store includes a hierarchal file system. A
plurality of files is located in the hierarchal file system. Each of the
plurality of files is associated with digital signature metadata
determined by a content of the file. A plurality of directories is
located in the hierarchal file system. Digital signature metadata is
associated with each of the plurality of directories and determined by
the digital signature metadata associated with the directories and the
files that are direct descendants of the directory. An update module
determines if an update to any of the plurality of files is available
based on the digital signature metadata associated with a root directory
in the plurality of directories.