| 摘要 |
<p>The invention concerns apparatus for updating a data file, from an earlier version to a later version. The invention compares the earlier version with a later version, and derives a transformation, which contains information as to the similarities and differences. The invention then processes the earlier version, using the transformation, in order to derive the later version, without reference to the later version itself. The invention allows multiple versions of an original file, such as bank records located at multiple locations, to be updated by transmitting the transformation to the multiple locations, instead of transmitting the updated files themselves. The procedure is highly resistant to interception of the updated data, because the transformation, in general, does not contain the entire contents of the later versions. <IMAGE></p> |
