PROCEDURE FOR INVISIBLE EMBEDDING AND HIDING OF DATA IN SOFT-COPY TEXT DOCUMENTS

摘要

Method of invisibly embedding and hiding data into a text document by modifying selected invisible attributes of invisible characters on a plurality of inter-word intervals, comprising the steps of selecting ( 10 ) at least one attribute that is invisible on the space characters used as inter-word intervals, transforming ( 14 ) the document into a canonical form by setting on all inter-word intervals the values of the selected attribute to the same default value, encoding ( 18 ) the data to be embedded and hidden into the document as an ordered set of values corresponding to the different values of the selected attribute, selecting ( 20 ) a set of inter-word intervals among all inter-word intervals corresponding to a set of space characters and replacing ( 22 ) on each space character of this set of space characters, default attribute values by the corresponding encoded data.