| 摘要 |
A method of generating a code representative of a passage of text uses in the preferred embodiment the character spacing between respective occurrences of a selected key symbol string within the text. The string may be fixed, or may encompass a variety of different forms. By comparing the known code of a target text passage with the code generated from a sample text passage, it is easy to determine whether the target text has been used within the sample. The method may be integrated within a copying device such as a photocopier, allowing the device report automatically whenever a user attempts to copy a document bearing one of a predefined list of sensitive or controlled text passages. |
