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.