A system for “horizontal” salting of database tables, text files, and data feeds utilizes a key field and character position within that field (the “Key Character”) and a Salting Field, which contains content that can legitimately be in one of at least two states without impacting the usefulness of the data. A unique identifier, which is assigned to the recipient of the data, is hidden within the data by using the variations of the states in the Salting Field to represent a binary 0 or 1, with the value of the Key Character identifying the bit position of the binary 0 or 1 within the unique identifier. This type of salting is invisible to the recipient of the data file, does not alter the accuracy of the data, and can be made unique for a particular party receiving data files or unique for each data file.